But if You Have a Fit & a Singleton?

A
Q J 8 6
10 7 6
K 10 6 4 3
J 8 7 Q 5 3 2
9 7 2 10 4 3
A K J 9 2 8 5 4 3
J 2 9 7
K 10 9 6 4
A K 5
Q
A Q 8 5

The other side of the coin. No trump, yes, over a minor, and you want to lean heavily in that direction on rather balanced hands with no glaring weakness -- such as a suit bid by the opposition or the only unbid suit, which invites that lead. Here, the bidding went a spade by South, two diamonds from West, double from North, pass, three no from South. Down one. Matchpoints: 4.69%.
I have said elsewhere that with singletons and a good minor suit fit, you'd probably -- no, nothing's certain -- do better in a minor suit game and might even have a slam with enough high cards to make you think of game in no trump. You can't know if your partner has a singleton, but you know if you have and if you have a good fit (by and large).
North's double has to be a negative double, indicating the two unbid suits, which is to suggest a good fit in clubs. South's three no bid with a singleton in the opponents' suit, seems rather perverse, and I can only guess -- well, it's the most charitable interpretation -- that he thought his partner was doubling for penalties, or in any event was announcing that he had that suit under control.
The defense rattled off five straight diamond tricks and didn't even have to solve any unblocking problem, while N-S have, clearly, a little slam in the cards. So . . . I would say be a little leery of no trump with a wide-open suit, a good fit with apparently good hcp count, and a singleton! <