That is one of the greatest issues, if not the greatest.
The fact that "spam-play" or really low level play in general is rewarded, or at least goes unpunished, which thus often punishes good play. This goes back to a game I played with a friend on Semoskiy, where we had them 'Semois Pinned' and yet they still can get out many T-34s (at least five) and even an ISU-152.
It makes me wonder if those two issues are, in fact, symptoms of a resource system that is also fundamentally flawed. Maybe I'm wrong, but now that every point gives the player fuel and munitions, if said player has been pushed back almost into their base, he / she can sit there and gather resources for a couple minutes until their next attack.
I'd rather comebacks be difficult and challenging than too easy and a common, expected occurrence.
You're fundamentally wrong here.
Comebacks are exactly what makes this game and makes it different to others.
There is no second RTS, where you can get pushed off/suffer losses and still recover.
Besides, on semois fuel point is right next to the base, so unless you were sitting on that, don't expect opponent to not being able to get armor.
Regarding spams, whole soviet faction is designed around one spam or another. This is why the tiers are inflexible and units in them effective in given role(except mortars, ZiS guns, SU-76, Katiusha, still somewhat penals who can't compete with ger infantry after T2 is unlocked).
Now, that being said, if player spams only one type of unit, it means the counter to it is that much more effective as you counter his whole force instead of single unit or a pair of a balanced combined arms.