Why, if it was all that and a tall glass of milk, did it only last two seasons? Because A&E got a new programming director with an ego the size of Staten Island, who didn't want any successful choices by a predecessor cramping his style. So Mr. Tabula Rasa tossed everything -- good, bad, indifferent, or great -- and remade A&E in his own image.
For what it's worth, laurie_robey and I have the series on DVD (but of course, it was released with some scenes deleted, because obviously it would be asking to much for them not to hash it up somehow), so I can watch what of it there is. The only problem is, like Jeeves and Wooster, Columbo, and Star Trek, I have seen it all several times and have large chunks of it memorized. What I want is new Nero Wolfe episodes. But let's face it, Monk notwithstanding  the day of the Sunday Mystery Movie are long past and not likely to return. Timothy Hutton, Maury Chaykin, Bill Smitrovich et al. are all still alive and well as far as I know, and there's no real reason they couldn't come back together to do it again -- other than the fact that they're not going to.
Ah well. I've still got Rex Stout's books to get through! They're all very good and there's lots of them.
 FWIW, I consider Monk more of a situation comedy than a mystery series -- the mystery element of Monk is always very lightweight, taking a back seat to being a character study of Mr. Monk's eccentricities.