On the 'I can dislike anyone for anything' argument - yes, you can. In the privacy of your own head, I don't see the problem with it.
But a central and important part of freedom is the right to challenge and (frankly) the moral obligation to be challenged. In a truly free (or Open, if you will ;) ) society, nothing ought not to be challenged and scrutinised. If you openly dislike someone for a reason that others see fit to challenge, they have as much right as you have to think it. The idea is that over time we filter out ideas that don't stand up to scrutiny. That's why people challenge racism/xenophobia/anything else.