I personally think it is weird and rude to have alcohol at a party, when the guest of honor would not drink. But, all I have actually seen at showers is punch, made with a tiny bit of champagne. I would think that it is a stretch to think anyone would get drunk.
I seriously hate this mentality. What if the guest of honor had an aversion to chips and dip? What if the guest of honor didn't like sweets? It's a party for the guests to enjoy themselves at, since they're spending money to come to it.
But, I also don't understand men who stop having drinks when their wives are pregnant. If I break my ankle and I can't walk, I don't expect my husband to stop walking. If I have a root canal and I can't chew solids, I don't expect my husband to stop eating foods that have to be chewed.