Its Deadly Devastation

The redouble pursued its deadly devastation on this hand.
K J
A Q 4 2
K 6 3
Q J 8 3
7 6 Q 8 3 2
K J 10 7 3 6 5
7 2 A J 10 9 4
K 7 6 2 10 4
A 10 9 5 4
9 8
Q 8 5
A 9 5 Vul: E-W

WestNorthEastSouth
1 NT Pass 2 *
Dbl Redbl All pass
* Alert (a transfer to spades)

This was the bidding at a couple of tables, and the result was devastating, as they met at the bottom of the scoring chart. Ironically, one pair let the double ride and made -- on an unwise defensive error. So they got a good board, beating everyone in 3 no, except a few that were doubled.
I don't blame the redoubler here. That seems to be perfectly consistent with his hand. "Pard, I've got some good hearts. If you've got any hearts of note and aren't bidding on a shabby 2 or 3 hcp's, I think we can handle 8 tricks in hearts. If you're strong enough for game, this should be more rewarding. Maybe they stepped into trouble, and if they wanna try the three level themselves, let 'em try. But of course if you don't have good hearts, we'd better retreat to spades." It's his partner I would put the blame on.
Two hearts? I mean, not the bid, but the holding? You've gotta figure your partner won't have more than 4 hearts. It's not that no one bids no trump on a five-card major, but even if this player does, you really can't expect that length on this hand. And I don't think you wanna challenge the two level on fewer trump than those guys hold. Further, you've gotta figure that you're getting a bad break, on inference from West's double. No, I would think South'd want at least one more heart for a slight predominance in the number of trump, expecting the decided advantage in hcp's to make up for defense's heart power being concentrated in one hand.
The 10 hcp's, traditionally enough for game opposite a NT opening might have seduced South into thinking they should have a good shot in 2 hearts. But 26 hcp's don't absolutely guarantee game, and indeed, not everyone in 3 no made here. Two hearts is just one trick less while granting the opposition a slight predominance in the number of trump, but almost all concentrated in one hand! No, it might have made, as one declarer did, but it's far, far too iffy to go for broke, for an absolute top or bottom, which the redouble made inevitable.