Aggressive or stupid?

I just played a low limit hand that has me thinking. It is a 6-max table. I am UTG+1, and I raise with ATo. I raise and I get three callers (family pot). The flop is Q 4 4. Should I bet this? I did, and I got three callers. The hand is checked down through the river. The small blind wins the hand with TT unimproved. Why did I bet this flop? Against three loose-passives when all I have is ace high?