I personally am strongly against any kind of "unlimited" vacation days or other such perks. In my experience hardly anyone takes advantage of them because they are made to feel guilty. Even most places that claim to offer working from home rarely have people take advantage of it due to the culture (not at desk means you're lazy).
I prefer the employer just to be upfront and if I want to work from home then I'll negotiate to do that once a week upfront.
These are two different issues. What you have a problem with isn't the "unlimited", it's the "no minimum". Would you have a problem with "unlimited vacation days, four weeks a year mandatory minimum?".
As in, if you haven't taken any vacation when December rolls in, see you after new year's.
I prefer the employer just to be upfront and if I want to work from home then I'll negotiate to do that once a week upfront.