Criticism does not mean being "anti". It does sometimes but if it's a complex issue and people take their time to understand it's various aspects, the critics are usually never "anti".

From Windows 95 I was hooked on GUI's. I didn't like Microsoft but I liked Windows. I'd almost never care enough about Microsoft to say anything but when it came to Windows I always had an opinion I'd want to air and it was always in the spirit of wanting an improved product. Mac OS 9 felt like a joke and the various Linux distributions felt unfinished.

But eventually I changed to OS X when one of it's later "kitties" came out. Among my friends who have a Mac I'm pretty much the first to ever criticize Apple products but if you look at how much money I spend on the platform and how much time I invest learning about it you wouldn't think I was a critic. I don't have opinions about Windows beside wishing IE wasn't such a pain to design for.

Being critical does not equal being against something. When your critics no longer want to share their opinion of your product or service, that's when you should be truly scared. That is when you're in a really, really bad place.