It has nothing to do with hygiene. It has to do with the authority of the rabbis to change the very commandments of YHWH.
Procedure and Practice
The procedure is to pour water out from a cup or glass first twice over the right hand and then twice over the left hand--care being taken that the unwashed hands do not touch the water used for the washing. The hands are then dried with a towel before partaking of the meal. A benediction is recited over the washing of the hands: "Blessed art Thou, O Lord our God, King of the universe, who has sanctified us with Thy commandments and has commanded us concerning the washing of the hands."
The reference to the command has to be understood in the context that rabbinic ordinances are also commanded by God. Observant Jews are very strict in this matter of washing the hands before meals.
Src
IOW, The rabbis made it up to prove their own power.
And the LORD spake unto Moses, saying, Thou shalt also make a laver of brass, and his foot also of brass, to wash withal: and thou shalt put it between the tabernacle of the congregation and the altar, and thou shalt put water therein. For Aaron and his sons shall wash their hands and their feet thereat: When they go into the tabernacle of the congregation, they shall wash with water, that they die not; or when they come near to the altar to minister, to burn offering made by fire unto the LORD: So they shall wash their hands and their feet, that they die not: and it shall be a statute for ever to them, even to him and to his seed throughout their generations.
There were certainly commandments regarding washing; to whom and when they were a requirement is one aspect, and that they are generally followed today among the observant is without doubt. So it is a logical tradition of men that was derived from commandments and had a healthy sanitary effect. Perhaps the problem is more that the tradition regarded the washed as morally pure and the unwashed as morally impure, sinful, while ignoring their actual spiritual condition. This would fit more with what is recorded. Washing of hands is good, and the blessing is good, if a man understands it in the spiritual and moral context. The water does not clean the soul, just the body.
Hand washing before meals and after bathroom activities is proven to extend life expectancy significantly. How would one deal with that reality if one believes Jesus and his disciples did not, and were not supposed to, wash their hands before meals ? A literal fundamentalist might forgo washing hands so he could be a true disciple. Hmmm ... not good.
These are scriptures regarding washing of hands in the NT (Luke 11:37-54, Matthew 15:1-20, Mark 7:1-8; I'm including Matthew 23:23 and Psalm 24 to sum it up). and I think this from Matthew makes it clear that Jesus was more concerned about the spiritual condition of a man than his ritual observances, whether they be in the Law of Moses or added as a tradition. The issue is not tradition but the moral condition of the people. Are they fulfilling the law of Moses in the weightier matters, or are they like someone in a religious ministry (Institute of Basic Life Principles for example) who adheres to a system of religion but is morally unclean. Then came to Jesus scribes and Pharisees, which were of Jerusalem, saying , Why do thy disciples transgress the tradition of the elders? for they wash not their hands when they eat bread. But he answered and said unto them, Why do ye also transgress the commandment of God by your tradition?For God commanded , saying , Honour thy father and mother: and, He that curseth father or mother, let him die the death. But ye say , Whosoever shall say to his father or his mother, It is a gift, by whatsoever thou mightest be profited by me; And honour not his father or his mother, he shall be free. Thus have ye made the commandment of God of none effect by your tradition. Ye hypocrites, well did Esaias prophesy of you, saying , This people draweth nigh unto me with their mouth, and honoureth me with their lips; but their heart is far from me. But in vain they do worship me, teaching for doctrines the commandments of men. And he called the multitude, and said unto them, Hear , and understand : Not that which goeth into the mouth defileth a man; but that which cometh out of the mouth, this defileth a man. Then came his disciples, and said unto him, Knowest thou that the Pharisees were offended , after they heard this saying? But he answered and said , Every plant, which my heavenly Father hath not planted , shall be rooted up . Let them alone : they be blind leaders of the blind. And if the blind lead the blind, both shall fall into the ditch. Then answered Peter and said unto him, Declare unto us this parable. And Jesus said , Are ye also yet without understanding? Do not ye yet understand , that whatsoever entereth in at the mouth goeth into the belly, and is cast out into the draught? But those things which proceed out of the mouth come forth from the heart; and they defile the man. For out of the heart proceed evil thoughts, murders, adulteries, fornications, thefts, false witness, blasphemies: These are the things which defile a man: but to eat with unwashen hands defileth not a man. Woe unto you, scribes and Pharisees, hypocrites! for ye pay tithe of mint and anise and cummin, and have omitted the weightier matters of the law, judgment, mercy, and faith: these ought ye to have done, and not to leave the other undone. Ye blind guides, which strain at a gnat, and swallow a camel. Who shall ascend into the hill of the LORD? or who shall stand in his holy place? He that hath clean hands, and a pure heart; who hath not lifted up his soul unto vanity, nor sworn deceitfully. He shall receive the blessing from the LORD, and righteousness from the God of his salvation. This is the generation of them that seek him, that seek thy face, O Jacob. Selah.
Also, fundamental in this is that Jesus was without any sin, the Holy One of Israel amongst us. Some Jews tried to ascribe sin to him for not following all the traditions as if they were commandments, while they themselves violated the very Spirit of the commandments, something all should watch for.