I think their objection is mostly for players that only rush to go kill enemies and don't care about inking the rest of the map. I think that's an okay playstyle to have, but it's sometimes really annoying when taken to its extreme, particularly if no gains that are strong enough are shown in return.
I think atr0cious pointed it out in a stream awhile back too; on Moray Towers, everyone's falling over themselves to reach the middle of the map and basically splatting each other over and over there. The ramps leading down to the middle get neglected, and it's actually pretty common that aggressive teams would lose just because they forgot to ink part of their ramps. It's really painful and I don't like doing this with the Custom Jet Squelcher, but usually when I come back and I see that the ramps aren't covered, I'm torn between getting down there and supporting with what's clearly a fighting centric weapon, or spending time slowly inking the ramps.