So, there's a risk vs reward and an opportunity cost involved, it's not abusive at all.
SwS Truck crushing, as during the release of WFA was extremely abusive, that's why it got fixed in a matter of days. It involved a free truck that could wipe out entire enemy squads without the OKW player ever suffering loses and bleeding MP.
Truck pushing can still be considered abusive if using the SWS trucks. The way I see it, it's a free truck that is unarmed but you can still use it to push/harass the opposing player's infantry preventing it to deal consistent DPS, there is no trade off and no downside to using it in this manner unless you over extend dramatically and lose it to concentrated fire, if you lose it good job you just tied down a sizeable enemy force for a few moments and captured the point/won an engagement, but if you do lose it you delayed your tech (But I don't think the penalty is that severe as you receive a new truck for free, not sure how much you delay your tech tough as I don't have OKW).
Whereas If you push with a kubelwagon, an M3, or an Ostheer Scout car, you are trading DPS for pushing/disrupting infantry because these units are most efficient at range to deal consistent DPS, so there's a tradeoff. Still, I don't consider SWS pushing truly abusive, but more of an annoyance. Lastly I'm fine with it as I rarely see it
