Whether or not OKCupid did the right thing here (they certainly got some press out of it), it certainly wasn't bad for the internet as a whole.
The scary thing about HN is that you might actually be serious that people should "simply write a web browser" to enforce correct political ideology...
Throughout history, groups have always sought to stifle alternative thought. The moral difference is in the tactics they use, which have ranged from censorship to violence and bribery to peaceful protest and civil disobedience. I, for one, prefer and even encourage peaceful public outcry of this sort. Say what you want, but if your customers (users, friends, coworkers) don't like it they don't have to buy from you. In fact, they probably feel a moral obligation not to. This doesn't only happen on the left - remember the Million Moms (or whoever) boycotting JC Penny for using Ellen as a spokeswoman?
I agree that people have the right to push for companies to select officers that meet their criteria. But things like the OkCupid stunt are less respectable IMHO.
Is that really the way we want to see the Internet going? Visit a website where the web client is technically perfectly capable of displaying the page, but was associated with someone of the wrong political ideology, and so they get a nag page instead?
There is no clean exit to that logic; shouldn't OkCupid have banned JavaScript at the same time then? Shouldn't they put up nag messages to people visiting from IPs that resolve to a Republican National Committee host?
And if you do the things above, when does it become a net neutrality issue?