You get out what you put in I guess, there's a reason col 100 on bf3 was nicknamed the poop bucket.
I think you're missing the point. The core gameplay of this game is about completing mission objectives, like capturing more points than the enemy or continuously breaching/defending objectives, not spending a lot of time upgrading weapons and unlocking attachments. Acquiring all weapon attachments should be challenging and time-consuming, but it shouldn't be that long.
Setting such high unlock requirements for weapons will only have one effect: discouraging players from trying different weapons. Everyone in the game will have the same weapon, and the strongest weapon will become the optimal or sole solution. Because trying new weapons/attachments is so expensive, you'll need to spend dozens of hours unlocking attachments for each one, and most people won't be able to devote that much time to every weapon.
