The Inkbrush is pretty bad in TC. I love the weapon and use it in ranked in Splat Zones and Rainmaker on a lot of maps, but in TC it's just atrocious. You cannot safely pressure the tower or safely defend the tower. Even if you dedicate yourself to getting as good at TC as you can with the brush, you are limiting yourself. You want to be versatile and able to fulfill the roll you need to fill for your team. Or, if not, you want your strengths to be useful enough that it compensates. The brush is good at the latter in Splat Zones, Turf War and it CAN do it in Rainmaker, but in TC you'll find yourself powerless in situations where you could really help if only you had a different weapon.