If there are complaints about 20% buffs/nerfs then I hope that we have no Lady Fist like buffs coming or else some might get a heart attack.
Other than that I can only say that in a PvE centric game like BL3 you can do drastic changes without ruining the game much more easily. And like stated above, it’s better to see what a drastic change does and if needed adjust from there than adjusting everything dozens of times. That way Gearbox also saves human resources (aka man-hours) to focus on more things in a certain timespan.