its used as a TD, assault gun, defense gun (v-base attacks) spawn camp breaker (harder to see due to its low sillhouette), NOT bombing a GV fight and many more things. also, never compare WOT to AH, they are so different the only somewhat similarity is the camping. and do you really want to think a TD that was intended for ambushes to really be out in front doing all the dirty work?
Nothing you've stated garrentee's people will up the Stug instead of a Panzer.
Assault gun? Panzer is better than the stug in that catagory. Theres no reason to up a stug.
Defence gun? Panzers still better. Plus when it comes to defence, most people just up tigers anyways.
spawn camp breaker? Not likely. Its not that hard to see. Multiple eyes spanning a spawn point, someone will spot it.
many more things? might want to name those many more things because the stuff you did name isent cutting it.
so far you havent named valid reasons how the stug would see more combat than the he177.
Also, Even tho Wot and AH are different, the tactics used in one can be applied to the other.