BRUTE directly replaced Breaching Shotgun. Pretty much the same PR as far as I remember. So any talk about Brute has to mention Breaching Shotgun, one was taken, another given. There is even a thread about it: I Have Plans I Cannot Reveal The Haters Will Sabotage Me - #18 by Tinker
Breaching shotgun did a lot. Any building behind marine lines could be completly leveled quite quick with just that, something otherwise only available to OB. So while BRUTE buffs marines on attack, breaching shotgun buffed them on defence.
Sure, they are not directly comparable, but it is pick your poison type of deal, let PFCs demolish buildings creating essentialy LV beach anywhere there was a building before, or let CTs have a long-ranged breaching tool.
Now I got a small idea, we got that transparent resin wall, right? What if it was very good at weakening BRUTE rockets effect? It sucks at anything else, so it is perfect. Gives xeno builders a reason to think a bit more and construct walls with layers, one regular, one transparent etc. Xenos can counter BRUTE, but it requires a bit of effort on their part, while OTs with BRUTE could no longer just shoot at any wall willy-nilly. Come on, it adds depth to xeno architecture and breaching.