To the OP – I agree; I think people just won’t settle and are Mevatel a Mitzva. This has become commonplace in our society.
When the single person is in their twenties, they shouldn’t settle for anything they don’t want; after that they should.
But what happens is- afterwards family and friends get involved. They say -you’re going to marry that -you Deserve much better! Unfortunately, the guy or gal doesn’t see the big picture. Then they listen to their family and friends. Eventually they become depressed and lose interest. This is all a Maasseh Soton. I believe the family and friends are going to give more of Din v Cheshbon than the actual person who didn’t get married.