I switched from linux to mac recently because my Ubuntu 12.04 laptop would randomly freeze after waking from sleep. I tried like 3 different solutions that I had googled but none of them worked.
So they think that people who work at medium to large corporations are better engineers than people who work at startups. Personally I've found the opposite to be true.
If it's a high salary, it benefits. In my experience, the ranges people in our industry get paid are sufficiently broad that not sharing your salary can result in serious offers that are, well, not so good.
I've found that most people believe x thing is true because other people also believe x thing is true. They won't say that's the reason but deep down it provides emotional support for their belief. So I've found it's best to not try to "rationally" argue with people and just change the subject.