People Rsvping "no" due to dry wedding?

Unfortunately, due to venue restrictions, alcohol is not permitted. We both loved the venue so much that it wasn't a deal-breaker to FH and I. We thought it was a little tacky to put that on the invitations, so we decided to list it on our wedding site. We thought it would be best to let them know ahead of time, so they wouldn't throw a fit once they found out at the wedding.

We mailed and hand-delivered our invitations almost two weeks ago, and we've begun to receive RSVP's back. We gave 18 months notice for the wedding and everyone had it on their calendars from the save the dates. People who said they were for sure coming now suddenly aren't (and we got the reply the same day they received that invite). We KNOW it's due to the lack of alcohol. We've even been getting texts that say "is there going to be alcohol?" (I mean, if you actually went on the website, you'd see the answer in capital letters). We've received several texts about the alcohol.

Idk why this is bothering me so much. I mean, if all they care about is the alcohol than being there to celebrate with us, then we shouldn't want them there anyway.

FH's family gets so stupidly drunk at family events that it's not even funny (it was one of the reasons we were fine with the venue not allowing alcohol). It's like they seriously need it to function. A lot of them are now choosing not to come because of the alcohol.

We've planned for several flavoured waters, iced teas, lemonades, sparkling cider. We are also having catered Italian ice and gelato for "refreshment hour" (we chose to call it that instead of cocktail hour, since there won't be cocktails). There will be so many little kids there, and we chose the frozen treats with them in mind.

Can people seriously not go and have fun for a few hours without having to complain about no alcohol? I bet people (who didn't go online to the website) will stop show up and be surprised and then complain about the lack of alcohol.

On the RSVP site, we asked people if they had any dietary restrictions and someone litteraly wrote that they couldn't drink anything WITHOUT alcohol in it.