In normal content, a Brute will hit the same target harder than the Tanker. The Tanker does better in AoE, for a few attacks, and then the numbers come down and the Brute pulls ahead again.
Take into account also the levelling process and what level powers unlock. The Brute is doing FAR better offensively than the tanker until late in the game. I understand that many people play as if level 50 is all that matters, but that's not how game balance decisions are made.
In 2011 Brutes were INSANELY OP. They did NOT need love. They got toned down so that they were not better at offense than Scrappers. Tankers are not back to where they were. They are still far ahead of where they were before they got buffed.
Scrappers SHOULD do better DPS than Brutes, as they do. And Brutes SHOULD be tougher than Scrappers, as they are.
EDIT: I could see a slight Brute DEFENSIVE increase, but increasing their offense will push very quickly into Scrapper territory. There was a time when SCRAPPERS were the class people complained wasn't worth using (even though they were exactly as good then as they are now).