It would be fairly annoying.
I'm actually starting to get annoyed with mercs altogether. It pisses me off every time I'm told that no group in a hotzone has room, meanwhile, it's a bunch of groups with 3 people, and 3 mercs. It's like, "really? you couldn't just drop 1 tank merc to let a real live player tank in? Is the damned merc really that much better?". I'd like to say something like, "nerf higher lvl(60+) mercs!" but then people would call me an idiot.
Its probably 3 boxers. I know when i box i have enough to do without having to try and keep up conversation and be friendly. Nerfing mercs would really hurt this game. In fact i would say that Mercs are the single biggest improvement this game has seen since the initial population decline started. I know i wouldnt play anymore if they nerfed mercs.
The population may be booming for now but its still a PITA to get a group together for basic XP content. The typical gamers mentality has shifted so far away from the grind that it just wouldnt work anyway. Back in the day getting 6 people together and sitting for hours and hours in the same spot was typical, these days people just dont want to do that anymore. The way the genre has shifted people prefer to get on grab a task or quest and go finish it. So now we have mercs, XP grind on your own time schedule and not be bound by the schedules of others.
Its easy to say "nerf mercs" now but if you got your way you would be regretting it the first time your XP group broke early because you couldnt find a healer. While i do miss a good old XP group and making new friends i dont miss sitting in LFG for hours and i dont miss sitting with 4 other people hunting down a tank or healer, i dont miss being all the way in an XP camp and losing a tank or healer just to wait forever and eventually just break anyway.