For what it's worth I feel like 90% of the people who criticize Gateway probably never had one and joined in on 3DS modding during the "OMG free gamez" stage of the scene. At the time Gateway initially released it was, for many, well worth it due to being the only way to modify games or play homebrew. ninjhax didn't show up until 3DS 9.2, so from 4.2 to 9.2 the only real way to have developed homebrew and modified games, for the average person, was Gateway (or using leaked CFW stolen from yellows8, which is arguably worse than using Gateway). I personally believe Gateway was fundamental in establishing the current state of the homebrew scene, at least for some developers. Others like smea and yellows8 had their own utilities and were slowly building up ctrulib on their own, but they can't always give out their tools so having something like Gateway available was good. I also personally believe having piracy behind a paywall was better for the time that it existed, the 3DS was very young and had a lot of titles to be released, now it's not nearly as secure to release for.
Not to mention the fact that currently all CFW, in it's current state, is based on Gateway. firmlaunchhax and memchunkhax were based on Gateway's implementations, RAM haxing QRs that people used for Pokemon were based on Gateway's exploit they released, and emuNAND code from rxTools was believed to be based on Gateway code, although that's not certain. But Gateway still pioneered emuNAND, however it's clear that despite having a strong starting team, it definitely must have slimmed down in numbers at some point. As for brick code, I feel like it's justified, they spent a lot of R&D actually exploiting the 3DS entirely when there was no public implementation, and they also had to develop their hardware, so they were simply protecting their investment.
