The old log spikes were more likely to maim a zed, taking off a leg so they became a crawler, than to just kill them.
They had many more hit points, balanced to materials of course, so they were more likely to survive a horde night instead of being destroyed.
The ones closest to your walls could be repaired during the horde. Sure you can repair the current spikes but there's a much smaller window to do so due to their lower amount of hitpoints.
While it's certainly possible to change the current spikes total hps, and damage output, so that they become similar to the old log spikes, it would seem that TFPs would have done so if they had intended to. So I'm guessing the current wood/iron spikes are acting as intended.
As to the playstyle. I'd very much like to be able to melee, from inside a base, in early, mid & late game, without the base build depending on certain AI behavior that faatal has said he is working on. The addition/return of something like the old log spikes _could_ assist with this, in my opinion. Example; turning a runner into a crawler spreads out the zeds.
I'm not sure the above is any more useful in explaining what I'm attempting to convey. If not then my apologies, not sure how else to say it
Edit: "What was your playstyle it would bring back?"
Specifically in a16, it was pole walled bases w a double row of log spikes in front. First day 7 horde would be a 5x5 made of cobblestone & maybe the inner row of log spikes upgraded to scrap iron. There could be some frantic moments trying to lure z's to another area when poles were about to fail, and trying to keep up w repairs to poles & spikes vs. smacking zed's w a club. I find that kind of horde defense engaging. And what I'm hoping will make a return: playstyle wise. Doesn't have to be poles or log spikes, just some magic sauce where I'm doing most of the work, not the spikes.