Nobody should allow kids to ruin the mashke table for the rest of us. Whatever happened to kids going to youth group/NCSY/Bnei Akiva/Pirchei Groups on Shabbos morning? Don’t shuls do a teen minyan anymore? Let them have their own kiddush.
Kids also do low-class things like take all of the same kind of rugelach, pick the meat out of the cholent, waste food, etc. In fact, with kids at a kiddush, they’re getting bad chinuch since the parents let them commit baal tashchis and borer.