Well, if you want to believe that the opinions expressed by the anal-retentive nancy boys who run that "grammarist" blog are more authoritative and reliable for word definitions and proper word usage than all major current standard English dictionaries, you are certainly free to do so.
However, the real honest truth is that, whatever its derivation, it is legal and proper English to use the word "marinade" as a verb today, according to all major English dictionaries, and those are the authorities I will rely on.
But this is I think one of the differences between a lot who support Trump and a lot who support Cruz.
For a number of Cruz followers, it's the 'rules' that matter. It doesn't matter if something works or doesn't work, hurts people or doesn't hurt people ... it's always the 'rules.'
For the basic Trump follower ... we say rules are good guidelines, but in the physical world - the real world out there as God made it, there ARE no rules, there is only the nature of the world, and Good and Bad are self evident.
So, for example, to say 'marinade' - everyone knows what it means. Everyone knows that the Colorado primary was a scam by establishment Republicans ... no matter how much they say it's what the voters wanted, or that the voters allowed it. Sure, technically, by the rules, they slipped it past them. I'm so glad the Republicans seek to slip things past the Voters. Seems like Cruz thinks that fine to because it's 'the rules' and he didn't break 'the rules.'
But for Cruz, as a lawyer, this anal attention to THE RULES means that you can claim always to be moral while in the background you are doing non-technically-proscribed things regardless of the self evidence of their rightness or wrongness.
That's why I can't support him - I don't think he's that very simple thing that all men understand - I don't sense that he's a good man. I sense that he thinks he does all the good things a good man does, from the book of good things, the rules. But that's a substitute. You see it a lot in the preachy type of Christians - often it's intentional, but more often than not it's a subconscious thing. Before Christianity, there was God and there was Good and Bad. What would Cruz have been as a man in that world? Without a book of rules, would have known intuitively?
That's just something I've noticed ... some fundamental differences between many of those who support Trump's candidacy and those who follow Cruz. One uses the book, and outside the book, all things can be justified. Trump supporters just kind of have a natural sense of right and wrong. Sometimes it matches the book, occasionally not - because the rules book is just a bunch of made up words to help clarify when things get confusing.
To defend the Colorado Republicans is just ... weird. But as a former boozehound, I can understand how the mechanism works. You don't necessarily know you're doing it. You know it somewhere - on a certain wavelength - that you're full of doodoo, so you just tune out that wavelength. It's not really denial, it's more just ... omission of a certain wavelength. The problem is that's the wavelength on which our natural understanding of good and bad, right or wrong transmits - what 'to do' and what 'not to do', once you tune it out for one thing, you don't hear the rest clearly any more, and that's why Ted's sleeping with the enemy, no matter how well he justifies it (or just doesn't talk about it) ... is a super duper red flag. I know it.
But I think Irish Juggler is trying to pick at a word to avoid the truth of what the context surrounding it was pointing out. If he denies the word 'marinade' then he doesn't have to face the reality of what that sentence actually means, and he knows that meaning, so he blocks it with his mind. When you use 'loser, stupid, cult follower' and whatever else he called Trump supporters all in about 20 words, you are marinating in a marinade of negativity, and you hear those voices all day long. Sometimes others are the subject, sometimes you are the subject. It's just how we're built - man's mind - that's what it does. It's not good or bad. The difference, Mr. Juggler, is that many live free of those words on a day to day basis, although if you give them to me, I will give them back to you very quickly, because I don't want them, you can keep the words 'loser, stupid and cult' for yourself. They are wonderful words! I hope you like them. Fine marinade.