Yes but if you kill them, you prevent them from using their paint X many seconds, which allows you to put your paint back on the ground. Killing them is part of the match, you can't just focus on painting the ground. 4 rollers isn't going to be successful in the long-run.
And from what I saw, people were complaining about its ability to OHKO which is one of the things you can easily avoid/prevent by doing what I said. Getting yourself killed before even being able to put ink/paint down only contributes to the Roller's "OPness". Once you deal with the Roller, you have plenty of time to get your ink back down over what they put. And often times, the Roller may not even come back to that spot and go elsewhere.
It's too early to call it OP, simple as that.