I have a hard time against Dynamos and Lunas as well, but I can't fairly call them scrubby because I personally cannot wield them effectively (especially blasters). Overused and arguably OP? Yeah. But they are viable as hell so there's a good reason for it.
I feel like a scrub when I use Aerospray and mindlessly rain ink down on a zone for the majority of the match, but I think its a role that sometimes needs to be filled. In these matches I usually end up with a very negative K/D in spite of a crushing victory. I guard the zone relentlessly so the team mates can all go and do their killing. Sometimes it feels really cheap and undeserved, but at the same time, if I werent guarding, my team mates would have a lot more to worry about.