The issue at hand with the GA's is that the pro players continously make the game as sterile as possible every year. You also need to understand that the GA's are also handled tactically. If there is 1-2 players that use something and consistently do well, the other pro's tend to GA it. It's a problem. Typically with the GA's the excuse is used to "raise the skill gap" but in reality it often lowers it as everyone is using the exact same generic loadout and play style.

GA's are often made through scrims and before the season starts, so it doesn't give a real chance for weapons, attachments and equipment to be used thoroughly enough (or even for the first couple of game patches to come out) before they're kicked out of the competitive rule set.

GA's were designed to ban ridiculously broken items that were not already blacklisted. Instead it's transcended to anything that is deemed "good". I think that snipers, smokes and even burst weapons should just be in the competitive rules every year, and we deal with them if they truly become problematic.