You're right about the H bonding, but there is another reason. HF has a (relatively) large delta G because of its ionic size (not atomic). There is a large decrease in entropy in an HF solution when compared to those of other haloacids. The small size of the fluoride ion makes the H+ F- attraction very strong. The attraction is weaker with the other halides because they're larger.
The extent of any reaction (in this case the dissociation of acids) depends on the free energy change. Delta G= Delta H- (T x Delta S). The decrease in entropy results in the delta G for HF being around 18 Kj/mol. It plummets for HCl, the delta G is about -50 kj/mole. It's even lower for HBr and HI.
When you have the delta G, you can calculte the equilibrium constant, Ka in this instance. Delta G = -2.30RT(log Ka). When you plug in 18 for the delta G, Ka is 6.95 x 10e-4, which is close to the list value for HF. The is a small eq constant, so the reaction is not one sided (which you already know is the case for HF). Do the same calculation for HCl, and you get 5.91 x 10e8, which is a huge K value. K values of that magnitude mean the reaction goes to completion (which you already know is the case for HCl.)