It boils down to the game being heavily weighted in favour of the human players, with far more skills being available, and those skills being better than their zombie equivalent (maxing out at 65% chance to hit for 10 damage, compared to 50% for 3 or 30% for 4, free running, barricading). Although changing headshot to remove the XP penalty is a good move (I can't tell you how frustrating it is to be on 90xp and have it zeroed almost every time), changing it to penalise the zombie player to the tune of an additional two and a half hour's AP seems to have gotten a pretty bad reaction.
To put that in perspective, for a new zombie player headshot will now cost them 15 AP - almost a third of the day's action points. To stand up on a maximum of 35AP is pretty pointless if you want to tear down a barricade or kill a survivor if you're not maxed out on combat skills. In addition, giving human players additional equipment through the addition of crates (which some zombies cannot see, and therefore cannot deny to the survivors) just heightens the feeling of being hard done by.
When it boils down to it, this is a zombie apocalypse game - but survivors outnumber zombies by almost three to one and last time I looked at the stats, there were more humans with Headshot than there were active zombies. Nothing seems to be done to correct the game being so heavily weighted in favour of the humans, so the people playing the zombies increasingly see their role as atmospheric set dressing rather than a competitive side of the battle.
I can see why people don't play zombies. To start out with a 30% change of doing 2 damage as your best way of killing (and more to the point, of earning XP) is not an appealing prospect. Indeed, I suspect the only reason I've been able to level my zombies is because I saved up 500xp as a survivor and bought up a few skills immediately when I died. From the characters I have running/lurching around elsewhere, the same's true of zombies as of survivors - it's more fun playing in a group - but levelling solo is almost impossible, or has been with headshot being such a powerful fun-killer.
There's a petition going around the zombie hordes at the moment in an attempt to persuade the game admin to add more Stuff for zombies and to concentrate on evening out the numbers. I don't think it'll do much, but I do think that something needs to be done before player attrition reduces zombie numbers even further - it'll soon because ridiculous.
Not sure what the point of the post is, other than to put this out there for discussion and see what people's opinions are. What do things look like from the survivor point of view? Are you guys getting any sense of fear over being turned to zombies for any appreciable length of time? Does it seem like a zombie apocalypse, or are the zombies not much more of a threat/annoyance than chav streetcrime IRL?