Im really tempted to say "player card please"...
Ill just make a few points and you can figure it out from there.
-Think about the different units that can hold sweepers. Think about their fighting capabilities and what happens when you give them a sweeper.
-Think about the feasibility of equipping all harassing squads with sweepers.
-Smarter players know when and where to place mines to increase the chances the squad wipes.
Mines need a change.
And I think, that people, who lose to "simpliest to counter" tool should show us playercard, don't you think so?
All engineers (except OKWs and maybe british) are not suppoused to be really good in combat, they are mostly support units. Giving them sweeper doesn't make them really weaker - they are weak already. Guess noone will cry about losing firepower by Pioneers or Rears.
And about smarter players. You know, I thought, that skill and mind in that game should be rewarded most, and using mines how you said like"place for increasing chanses of squad wipes" - this is it. If your enemy is skillful and smart enough for to use mines right - it should be rewarded, not punished.
What people say about "my *squadname* insta died from mines, nerfnerfnerf" is simple whine and L2P issue. Buy 30 ammo sweepers, use them with your groups and you will be able destroy way bigger enemie's ammo investments into mines.
That nerfing mines just will make one of "toughest" sides of already poor USSR weaker. That is one of the reasons, why I think, that nerfing mines is really bad idea...
P.S. Case with mines in CoH 2 reminds me Techies in DOTA
Techies mines are deadly and insta-kill you but... when you getting sight - techies sux. Same here - getting sweeper, and it's gone! Btw, I think, if Relic find mines so dangerous, why not to add tank mine rollers? 
Relic Entertainment
