Not everyone who opposes gay marriage thinks of gays as lesser than them. Some oppose it for religious reasons, for example. Also, what about views on other exclusionary policies? Wherever you live, I'm sure many people in your country think that no foreigners have an inherent right to gain citizenship and residence in your country. Perhaps even you feel that way. This is an exclusionary view and therefore should be punished by prohibiting those people from holding positions of power... right?
Besides, you are still missing the main point. Discriminating against people for their opinions is nonconstructive - by excluding them from dialog, oppressing them in daily lives and proudly putting your intolerance to their views on display, you just make them angry and more entrenched. That kind of demonization might feel really nice (when you're on the giving end of the stick), but it works against liberal values in the long run. Where do you think Trump and Brexit came from?
Besides, you are still missing the main point. Discriminating against people for their opinions is nonconstructive - by excluding them from dialog, oppressing them in daily lives and proudly putting your intolerance to their views on display, you just make them angry and more entrenched. That kind of demonization might feel really nice (when you're on the giving end of the stick), but it works against liberal values in the long run. Where do you think Trump and Brexit came from?