I don't blame 'em, if Pioneers can't be as strong as main infantry, then why can Engineers? Now they're both inferior to their infantry counterparts. The difference in DPS compared to the old rifle isn't even big, it's 1-3 less for the most part.
Engineers never were as strong as main infantry, since they're a 4 man squad compared to the standard Russian 6 man squad. I'd much rather have a pioneer than an engineer in most fights. That said I don't really care about the nerf
M3s are only useful for quite a short time vs OKW, since you can get a Puma pretty damn fast. And before that, just get schreks asap, and keep your units (especially sturm pio + kubel) together. T1 is not that hard to counter.
Also, buffing the raketen just for the sake of gaining an advantage against Soviet T1 would be bad balancing. OKW already has a shitload of AT, no need to make that even stronger.
Ehm, in the upcoming patch OKW still has a very strong early game. The kubel gets a 5 fuel cost, but that doesn't make it any less strong as it is right now.