Those opinions are very subjective, yes soviet community doc might not be good, but not because that it's bad, it's just that rifle grenades right now are crazy.
Even if you removed riflenades from the game, you are still sacrificing all your commander abilities for 1. A super bad ZIS for 200mp 2. An expensive maxim that has the ability to kill T2 vehicles if your opponent drives straight down the firing cone and you saw it coming beforehand 3. 120mm and 4. A really bad version of smines. With the drop in T2 cost these units are worse than ever, and they never were any good after the initial halving of the dshk dps.
Conscript support? Why is it bad? It gives your conscripts alot of versatility.
Rapid conscription is extremely gimmicky and pretty much never worth using over any other kind of munition ability. Hit the dirt is just yellow cover that is asking for a tank squish or riflenade. ppsh are a weapon you're better off without. All this really leaves is incendiary barrage (available in plenty of other commanders) and conscript repair (ditto).
Even before when ppsh was still useful and by extension hit the dirt was a bit better, this doctrine still didn't offer anything over the more versatile ppsh doctrines that gave you a unit call-in.
Shock motor heavy vs mechanized support? Why are shocks troops bad? That is a very subjective opinion on whether someone prefers shock troops or gaurds. On a close range map like stalingrad, i would much rather choose shock troops over gaurds. Mark vehicle? Well since the isu-152 is getting at buff next patch my guess is that the mark vehicle is sort of going to be overkill next patch, the ISU-152 is another thing. It not being viable is going to be addressed in the next patch. Right now the ISU-152 is worse in anti tank than the IS-2 for some reason...
Because they are, sorry. Shocks are the most worthless unit in the game for cost right now. But let's ignore that and pretend they're useful: Mark target is the single most powerful antitank ability soviets get. On the other hand armored detection is among the worst commander abilities in the game, it's just a waste of muni that does nothing you couldn't do by just listening to game sounds, looking at the graphics in the fog or just using the 3 times cheaper and twice as effective tracking on several soviet units at veterancy 1. So basically it's shocks+conscript repair vs guards+mark target+AT gun camo (arguably fairly useless). There is just no contest if you ask me, just mark target alone is better than shocks+conscript repair combined, then you get guards on top of that.
Why is german defensive doc bad? Tank traps have low health, but that still doesn't make them useless, for example festung armor has a pak 43, and has railway arty instead of sector arty, in my opinion,sector arty is way better, since it basically shuts down an entire sector for a minute.
No, their health does in fact make them useless. A tank trap that dies to two shots from a tank isn't useful in the least. Sector artillery is the easiest to dodge artillery in the game, and is extremely map specific to boot. Trenches are arguably better right now when conscripts are so weak that molotovs are rarer. Of course there is actually no reason to make them because soviets have a far easier time to get stuff out of them than germans so they're just a risk. And hull down is the least used german commander ability period, and mostly for good reason (while the bonuses are ok, it just doesn't fit any gameplay situation you realistically find yourself in)
Sector artillery doesn't shut down any sectors, as long as your units are constantly moving and don't have another unit following them in the case of infantry (you can have two or even three vehicles trailing each other because they're much faster), sector artillery will in fact never hit a thing. It has no movement prediction whatsoever.