Back in the days of the MG42 bulletin and pre-nerf, it was clear you had to nerf MG42s. Still, when they had area suppression as powerful as the vCOH MG42, blobs were not a problem at all.
But why were they so powerful? One answer attack-move plus the new capping system. In vCOH you couldn't afford to cap with an MG42, at least unless you were sure the field was clear. That amount of suppression plus the ability to cap was simply too powerful.
And I still don't see a good solution to the problem. The new capping circle system has a LOT more to do with balance problems than people think.
I never though MG42s at their peak were OP. I rarely encountered someone spamming them, and if i did soviets always had reliable counter through oorah, molotovs, morter, clown car, shocks smoke etc. USF are also well equipped to deal with them.
BUT, its just to hard for many people and relic have simply rolled over to attract more players.
There are numerous ways relic could change mgs to make them effective but i don't think that is a direction they wish to take because even though blobbing is annoying for some it is the preferred playstyle for the many casual players that exist in this game.