I suppose that's true, but in the field where I work (social science), servers are mostly spun up to scratch an immediate and idiosyncratic itch, so configuration tends to happen organically.
I agree that's probably not a good idea, and learning Pupchefsible is well worth the effort. In the meantime, though, there's at least some degree of reproducibility with etckeeper.
I do this stuff professionally, and I've learned the hard way that you either have a reproducible environment or you don't. etckeeper isn't reproducible. Actually rolling back with something like etckeeper is much, much more likely to break something (by deleting a config file used by a newer service, say) than to save you. If it did something like separate branches for each service or component within /etc I might be more sympathetic...but at that point you have half of a CM system already and might as well just go the rest of the way.
If you need reproducibility without a CM framework, keep backups of your machines.
Manually modifying servers was never a good idea; it's worse now, even with tools like this.