A lot of good points here but he might not have seen the flip-side, and that's something that can sour someone on startups real fast.

Here are a few that I've run into:

A lack of funding and the headaches that come with it like downsizing, cost-cutting, and just the general absence of job-security.

Having a visionary CEO who is also crazy or incompetent or both.

Having a really nice product and it going nowhere because it's either ahead of it's time or behind.