Why is providing necessary capital to startup companies is necessarily vulture and/or evil?
Some are, but it's mostly for those companies that are "in distress" — there are enough VCs and so much money floating around that for many startups there are a lot of opportunities to pick a firm that will provide not just money but also direction and experienced business advice along with potential symbiotic relationships with other companies, usually overseen by some position(s) on the company board of directors.
Quite a few startups have an idea or a product, but very little in the way of the business plan. VCs might be the ones who would see the bigger picture or the market(s) and have the capital and relationships to make it into reality.
VCs often become good partners. Cisco and appointment of John Chambers to CEO is just one such example.
Some may...most do not.....