Well, it is quite understandable why there is no M32.
First reason: in order to be balanced, the power of single grenade from a weapon that can deliver 6 rounds in such a short time had to be relatively low. That's what we have in KF1: a simple gorefast can withstand a direct hit, sirens get bounced around the map like rubber balls, and a whole mag is not enough to kill a scrake. That approach is immersion-breaking. And if explosives are to be powerful as we imagine them to be - they have to be slow to deliver and in limited supply.
Second reason: destructible environments. A single chum armed with M32 could just destroy everything there is to destroy on a map during a single wave. Suddenly all the effort of making detailed, object-filled maps and advanced enemy dismemberment engine would just go to waste in a matter of seconds. I believe it's better to see the areas gradually deteriorating through the whole game.
Third reason: technical stuff. Less powerful PC performance issues, crazy physx behavior from multiple explosions at once, constant smokescreen and general mess in terms of gameplay balance.
So yeah, quality over quantity is a change for the better here.
I still don't like the idea of grenade pistol, though.