I understand the desire for age limits in relation to who you want to interact with online. Ageism is a real thing, but if you’re not into men over 30, you’re not into men over 30. At your age I was exactly the same.
Why don’t you say “Please be under 30” or “I’m attracted to men between the ages of X and Y” instead of “Don’t be over 30”. I know it seems like a small difference, but it’s really a big one. One includes people (all those under 30) and one EXCLUDES people (all those over 30). One states what you like, the other states what you don’t like. Stating what you like is a preference, stating what you don’t like is a prejudice.
When I see any profile that says “Don’t be this, don’t be that” I immediately think “What a douchebag, who the hell does he think he is?”