If there's one thing Frasier can do that perhaps no other show can is the depth of character development that spans over generations. I watch David and understand the spoken and implied elements because I've followed Niles and Daphne for years. I watch Freddy and understand his nuances because we've known Frasier and Lillith. I also get his being a firefighter because I've known Marty and Ronee, and perhaps those ethics, heroic everyday man skipped a generation. The very first episode opens as "the Good Father" so fittingly named because we've followed his bachelor and husband days, to his days working on being "the Good Son", and now "the Good Father". It highlights what this series can uniquely do.
Most of the critics of this show are busy comparing it to its yester-years. What it WAS in the 90's, how his witty remarks WERE, how current characters compare to previous ones like Niles. Or others say they get something too reminiscent without the cast to support. What I think they miss, that most die hard fans seem to catch, is his evolution from all of the characters and events of the past that have molded him into what and where he is now. Of course there are familiarities because it's the same man; of course there are differences because he's evolved.