Daphne believable as the object of such idealization?

I think it's also her English accent. I just started watching it and wish I could meet an English woman like her. She reminds me a bit of Jenny Agutter in An American Werewolf in London.

A pot for every kettle, so to speak. My hot won't be your hot, and doesn't have to be. And Niles was concerned with more than just looks. And he was also dealing with Maris, so anyone who was kind to him was good

It depends on the woman and the man. There are plenty of women in this world that may seem plain and normal to you and I, but for each of them, there's a dude out there who really does think she's the be-all and end-all of women.

Daphne was a really sexy young woman the first few seasons of the show.

Niles fell for Daphe because she was the anti-Maris: unpretentious, friendly, working class, not “insect stick thin”, and perhaps an unspoken regard his own working class roots as Marty’s son. He and Frasier seemed to have been driven to pursue the Ivy League lifestyle by their mother, but there were always hints of Marty’s influence on them too.

Also, it’s not as if Daphe was attracting other men left and right. Most of the early years of the show featured Daphe struggling to get dates. She was engaged to that pudgy little lawyer guy before Niles too.

As others have already posted, one person's bombshell is another's ordinary, and vice-versa. Also, it wasn't just Daphne's appearance, lovely as she was, but her overall personality. She radiated warmth, kindness, but also a firm no-nonsense manner. In short, she was desirable for more than just looks. And considering what Maris must have been like, she would indeed seem like a goddess to Niles.