I love coptering too, but you've got to figure that a movement system that isn't presented to newbies as a possibility in-game, and that people use specialized melee weapons to get the best out of, isn't going to be very good for getting new people into the game.
I mean, speaking only for myself, I remember it was a bit touch and go in the first few days, because I had no idea what was going on - teams were strung out, and I (who obviously had no idea of the maps) was left waaaay behind, feeling like a complete chump.
If it hadn't been for the fact that I particularly love the art design, I probably wouldn't have persevered, discovering this "coptering" thing on the forums, etc. I would have just shrugged and uninstalled as it didn't feel like a PUG-friendly game at all out of the box.
Basically, coptering is alienating to new players, and I think it was a terrible decision to keep it in when it was discovered, they should have nixed it immediately - and/or, if they felt the fact that people took to it suggested people wanted a faster movement in general, they should just have implemented faster movement (maybe with a small skill ceiling, but not so high that newbies couldn't at least make a start of it, and generally keep up with teams that wouldn't be too strung out).
I think DE sometimes take too much heed of what their players say. I mean it's wonderful that they're so responsive and all, but they need to stick to their guns more.
Another recent example is the GMag. They've dug a hole for themselves because they made Augments tradeable - if Augments weren't tradeable, GMag wouldn't be an issue because it would filter out new players (who at the moment can get a GMag for a few boss runs and a bit of plat) and keep GMag as a specialist tool for endgame farming efficiency amongst relatively more experienced players (obviously DE have nothing against building/composing for farming efficiency per se, otherwise they woudn't invent things that make farming efficient, like GPull, at all). As it is, the GMag/Mesa combo has taken over the meta like a rash, hardly anybody asks for anything else. That's a whole bunch of relatively new players acting like lemmings.
So DE should have stuck to their guns and made Syndicates the one element in the game that requires hard choices and a consideration of real cost. But no, they had to cave into pressure, just like they caved into pressure re. coptering because it was cool, and they wanted to look cool and accepting of emergent gameplay (which is what seems to have happened, might be wrong).