Or you don't expect minions to do heavy lifting they're not supposed to be doing.
If you have a team that kills minions en masse like that, you don't create encounters with 15 minions and 2 normal monsters. You also don't put solitary solos against a stun-lock group.
You just don't put together 'easy mode groups' for the players.
That's not a fault with the minion mechanic, which works just fine for most groups. The DM chooses the encounter, and not all encounters are appropriate or challenging for all groups.
This fact hasn't changed in decades of gaming. No system has been made where it isn't true. I don't expect 4th edition to be different.
Every single group I've played in has had some trick to minimize minions. Sometimes without even expecting it. Early in 4E, we were playing through Thunderspire Labyrinth. We ran into a room where dozens of demons or some other minions were summoned against us, in a relatively small space. One character had a Lightning Weapon from earlier in the adventure, and unleashed it against the boss - and we discovered that it fried pretty much every minion in the fight.
It is true that every group has its own strengths and weaknesses. But I'm not sure why you think "Just don't use minions" is a better solution than "find a house rule that allows minions to still be used." I mean, I like the concept if minions. I enjoy using them, and players enjoy fighting them. Why shouldn't I try to find a way to keep using them?
Similarly, why shouldn't I find ways to present challenging solos to groups that can stun-lock?
If all of these encounters and elements work for you, that's fantastic. But for those who have had problems with them - and, clearly, quite a few folks have - it seems far more useful to brainstorm ways to use them, rather than just dismiss it as an issue and tell people to just stay away from that element.