Whether it's a small startup that's using a generic contract they've gotten from the internet or their lawyers, up to massive corporations, they're all going to include semblances of some of these points. Probably for different reasons, but the points will still be in there. Startups and small companies might be more flexible to work with you on changing parts, but still the legal headache of changing anything is often far greater for the company than just passing on you and looking for another candidate. Infinity moreso for big companies.
My experience is biased towards technical roles (like most on HN), but I've worked for startups, big companies, and as a freelance contractor. It's the same stuff in most contracts. Obviously my experience is not indicative of 100% of companies and I'm sure I'll have people chime in saying they had success getting company X to change some of their contract, but it's overwhelmingly not going to happen. So to treat these points as 'rules' instead of 'points to be aware of' is a bit too hardline of a stance to take in my opinion.