I would argue that no weapon is good in the hands of most people.
Fair, but the Aerospray is a weapon with an intentional below average combat ability designed primarily for turf, given its low range, low accuracy, and low damage. Stick that onto players who aren't the most combat adept and you got a double wammy.
While Turf War is a mode which is based on turf coverage, that alone will not win most matches. Combat is still important and if you lack the ability and the equipment, you set yourself up for disaster in the long run.
If you do have smarts to have combat aptitude with the Aerospray, great, but most people aren't. But otherwise, I think a lot of the people using Aerosprays would really benefit more from using more rounded weapons, like a Splattershot or even an Octobrush, and having a play style which is more rounded.
Non-combative play styles really aren't that great, some degree of aptitude in either offensive or defensive combat is really necessary to find consistent success. Finding a weapon that helps reach that middle group if part of it.
Which is why I don't like seeing Aerospray users that much, since they try to push one aspect too much they ignore the other important half of Turf Wars.