With the new zombie respawning feature, gameplay has worsened as we are practically facing an endless stream of zombies that come to attack us one after each other, making them practically invulnerable. Hence, it is pointless and frustrating to kill a zombie as a clone of it will immediately re-attack us afterwards.
The number of zombies in the game should be high, but not infinite. Let me make an example:
Case A: a lone survivor hides in a house.
Case B: a team of 30 well-fed and machinegun-equipped survivors with a lot of ammo combs the city, hunting and exterminating all zombies.
It would be normal to expect that in Case B the city would be zombie-free, at least for a while. Instead, as zombies regenerate, the city in Case B holds in any moment the same number of zombies than in Case A - which makes no sense.
Timing should be changed so zombies respawn no earlier than 7-10 minutes after being killed.