Players are concerned that with this new ’low ammo’ sound, it is no longer necessary for you to keep track of how many bullets have been expended by your opponent. All that your opponent would need to do now, is listen for the clicking and know exactly when to pop out. This, essentially ’lowers the skill required’ to beat the opposing team.
Although there have been complaints from some players, others are saying that it has minimal impact and won’t sway the game that much. Some argue that most players are not counting bullets anyway. Aside from that, you would have to be relatively close to your enemy to even be able to hear it.
Regardless of whose argument may be correct, the reaction to this change was much more than Valve anticipated. This may bring about a change in how quickly updates will be introduced in the future. Valve has yet to comment on the complaints, and the widely debated sound effect is still in place.