DPS meter stuff was implemented long ago...I certainly did it. It doesn't require you doing any nonsense with your play screen anyway - the G15 integration prints out your dmg, and you don't need a G15 keyboard to read that data either.
My issue with this new one is that it connects to a server to load everyone's DPS into the meter, not just your own. The concern is that raid groups will insist everyone install this (highly suspect and, despite their claims, potentially bannable) mod, plus OBS for screen-capturing, or GTFO. As Morokh points out, it's basically a new level of "LFG dungeon full zerker only," but one players have to jump through a lot more (fishy) loops to deal with.
It doesn't affect me personally, but it does make the community more toxic and pushes the game further into territory I wish it would avoid, but at this point I've pretty much given up on the game ever getting back to what I enjoy so it only elicits a great big shrug.
"Bads" are real in MMOs. It's often not even their fault, but the fault of the lack of DPS meters. When you introduce a "bad" in FF14 to the (illegal) DPS meter you literally will see their DPS increase 4x as they figure out what actually works now that they can actually see numbers.
The problem with DPS meters (and Gearscore, asking for achievement points, etc.) is that they're only provide a narrow definition of how someone plays, but are used by the community to pass judgement arbitrarily. For example, DPS meters
only track DPS, so that becomes the metric by which everyone judges a player's performance; it excludes things like applying boons and clearing conditions (which improves
everyone else's DPS), splash healing, and all the other stuff that was supposed to be important in GW2 but has fallen by the wayside (and with the way raids functions, doesn't appear to be coming back any time soon).
Likewise, Gearscore looks at a player's gear and summarizes them based entirely on that; maybe they've been unlucky with a drop, haven't played in a while or (my favorite catch-22) they can't get the gear needed to do hard content because they haven't done the hard content to get the gear needed. It gives absolutely zero information on how good of a player that person is at actually playing the game.
AP is just as stupid; it doesn't track anything other than how many achievements you've chased down. Someone could theoretically max out their WvW and PvP achievements and get into high-AP PvE groups without anyone batting an eyelash.
All three are ways for people to apply a single numerical value to a player that allows them to pass judgement, without knowing how good of a player they really are. In the same way having good gear doesn't make someone a good player, knowing the "optimal rotation" and being able to actually execute it are two different things (like that ridiculous 30-something step rotation for engineers that's impossible to pull off on anything but a target dummy) and min/maxing is not indicative of skill. If they were just used as a tool to improve, that'd be fine, but that's
never how it works out, and in a genre where the community is bundled right into the gameplay, the bad outweighs the good.
If you weren't pugging raids or didnt care about monitoring your own dps, I really think the effect will be minimal.
The only effect it has is that the shit tacos of the world get a little spicier.