Yeah when the pgren sprint camo meta comes around you tell me. MGs are intended to counter advancing troops, their drawback is setup time and limited firing arc. Both grenades off CD just says you're incapable of smoke and flank and instead just want to run headfirst into an MG, smoke it and then attempt to wipe it for the expense of 2 button clicks.
Everything you just claimed here could be said about sprinting PGrens and maxim. In fact bundle nade is far more devastating compared to firecracker nade Shocks have, and maxim is far worse at stopping sprinting/smoking troops compared to MG42 yet that combo is not a problem for you while Shocks nades are?
Also post again when Shocks become meta again, because PGrens are quite common compared to Shocks.