> If you don't stand for yourself, you are unlikely going to stand for other things, seemingly less important and employer may see this as a bad trait.

I don't think there are many situations in which an employer is positive about a non-executive employee rejecting their contract offer and proposing an alternative with fancy legalese clause awarding themselves a [$amount] bonus up front in a manner which creates the most complications for the company's lawyers and auditors. It's certainly something (and someone) very easy to say no to.