For every Frasier sent to bedevil an unfortunate Marty, along comes a Niles
When Frasier was good, it had at its core, one brilliant creative decision. In Frasier Crane himself, it had the perfect prig, a deeply anal-retentive person who was redeemed by his essential good-heartedness. So the obvious thing would have been to install another main character who could play a regular guy, an Oscar to his Felix, which in a way was accomplished with Marty, the unfortunate father who had been doomed to live with Frasier and to endure all these pomposities.
But the stroke of brilliance, was Niles. To introduce a brother who was even more priggish than Frasier, even more anal-retentive, a Felix to Frasier's Oscar, was an act of almost reckless bravery. Yet it was the making of the show.
Now poor Marty was up against the two of them, the double-Felix. And when it was good, you'd have Niles speaking wistfully about this little mountain village in Italy in which there is a great and legendary cobbler, whose beautifully made shoes are celebrated by all the townspeople. To which the bullshit-detector Roz responds, "Gee, there's a place that needs a bowling alley."