But apart from the obvious derp-juking, there's:
Deployable Shields. Sharpshooters. Reapers. Scouts. Cloaked Infiltrators. (anything with good gap-closing really)
Honestly, Rocketeers and Bruisers are very easily countered. I'm far more afraid of Grenadiers than either of those.
Which isn't to say there aren't good Rocketeer players, but the rank and file folks (like at my MMR) don't really think to much about how to use them.
Edited by Atmos_Dwagon, March 06 2014 - 08:28 AM.