You are arguing two discretely separate things. No one thinks anyone who chooses not to drink is a problem. Not wanting alcohol served in a certain context has nothing to do with those who do or do not drink. One could drink and not want alcohol served in MK (likely for historical reasons). One could also not drink and have no problem with alcohol being served in MK. Exclusively not wanting alcohol served because one does not like alcohol is perhaps moralism.
Which then boils down to is it odd to have alcohol served in MK? I don't think MK's primary audience should be 'children', so I'm happy if they get away from that. The audience is literally every demographic, there should not be societal shame in enjoying MK without kids.
However, historically the park avoided serving alcohol, so it would not be that odd to continue to do so. On the other hand purporting to have 'nice dining', in a vacation destination, without alcohol, is also odd in today's standards.
So, it comes down to tolerance for change more than anything and personally seeing it as a pro to broadening the demographic. For me at least. Toys R Us is likely never looking to appeal to me.