I don't know what your definition of "fine" is but they are BY FAR the worst combat infantry unit in the late game.
Grens - excellent vet bonuses + LMG or G43 + long range grenade + snare
Rifles - excellent vet bonuses + BAR/Mwhatever + strong grenades + snare
Volks - amazing at Vet5 and strong AT + various grenades
Tommies - strong vet bonuses + LMG upgrade/light AT + strong grenades + doctrinal snare
Conscripts - snare, lame grenade, no LMG, mediocre doctrinal short range upgrade
they're also the cheapest, even factoring in the ppsh or ptrs upgrades. they are certainly the weakest, and that sucks for soviet players who use them, but i don't think they're disproportionately weak for their cost. they have two main issues, well three if you count getting to vet 3. one, as i mentioned they're generally fighting more expensive infantry but cons are not enough cheaper to really counter spam, plus there's the issue of population which certainly comes into play in team games. two, while cons are generally fighting more expensive infantry, they have no non-doc upgrades and their doctrinal upgrades are mediocre at best. this puts them at a severe disadvantage against upgraded and/or more expensive infantry. it doesn't help that they have a short ranged and, as you mentioned, shitty against everything but garrisons grenade.
i guess the summary is, i think they're ok for their cost but i think they are easily the worst of the mainline infantry due to both a lack of upgrades and a lack of power. additionally they don't have very good utility.