I've started making vacation time a major part of the negotiation when taking a new position and in all instances I've brought it up during the interview process the interviewer acted alarmed. Even with my current position with a really cool small web shop they ended up interviewing me a 2nd time before offering the position. The key topic of conversation during the 2nd interview was basically the CEO trying to figure out if I planned on taking time off in some unspecified but inconvenient fashion that would leave the company in a bind.

Sort of. The difference is that some benefits are linked to length-of-service or continuity-of-service, so an unpaid vacation in the USA can scuttle your health insurance, equity vest, 401(k) match, etc.