I agree with Katitof. The PTRS is fine and is much worse compared to all other infantry AT options. People are just so used to steam rolling Soviet infantry that any form of competency hurts their feelings.
It has a different use, geared far more heavily to fighting Lights than mediums and Heavies (Though I'm not really sure why).
As I've said before, I think the Guards implementation of PTRS is far better than the Penals one. Guards supplement the lower damage/alpha strike power of their PTRS (relative to other factions' handheld AT) with strong utility abilites (Button), and of course their AI performance.
Penals are being pushed in a direction of trying to force their PTRS to compete with Zooks, Shrecks, and PIATs in terms of "brute force", which doesn't overly suit the weapon's design. I think trying to design an interesting utility ability for PTRS Penals would have been better than just giving them another rifle.
Either that, or give them lend-leased Zooks instead of their PTRS, if you want them to more closely parallel other factions' AT squads.
I still wish Guards were Nondoc and Penals had some other role than trying to be an AT squad, but this is extremely unlikely to happen.