I strongly disagree.
It actually IS a nice genre-novel in the style of the Sam-Spade/Marlowe-tradition.
It also has a science-fiction-touch, which would be completely nuts and useless if not for the funny conclusion of the aliens to not colonize this planet, since it's so damn shitty.
But most of all:
even though it's not an autobiographical story, the main character is pure Bukowski/Chinaski.
Don't you see the total tristesse through the whole book? (it's not only the rain.)
And that humor all around, like when he thinks about, what he has to do next and always ends up drinking, or when he gets into arguments with barkeeps all the time ("Sorry, baby, but I seem to get into these negative dialogues with almost every bartender I meet.").
And how he handles Lady Death, knowing Hank himself would be her next victim, is just genius. ("But you always seem to be hanging around me, Lady." - "I hang around everybody, Nick, you are just more aware of me.")
I'm sorry, kids: I love that novel!