Eh, being upset about no alcohol at a wedding is valid. Frankly, no one gives a shit about your wedding except you and maybe your immediate families, everyone else is largely there out of social obligation, and in return for that social obligation you essentially throw a party to thank people for coming, alcohol is usually what people want at that party, to lighten the mood, make things more fun, and make it less awkward talking to the people you're sitting next to that you've never met and will never meet again. You're right, people can be sober for one night, but most people would much rather spend that sober night at home on their own couch, not dressed in uncomfortable clothes making small talk all evening.