I've noticed this - but for me it's not the comedy per se, it's that modern authors (particularly in the noir style) want their detective to be a constant sourc

I've noticed this - but for me it's not the comedy per se, it's that modern authors (particularly in the noir style) want their detective to be a constant source of witty comebacks. You feel like the other characters are just there to deliver setup lines, so the detective can amaze us with his devastating zingers. Ironically, Raymond Chandler - whom I imagine many such modern authors are trying to imitate - commented somewhere in his letters that the detective should almost never get the punchline. He pointed out that it was more effective to have the bad guy deliver the zinger, and the detective just take it on the chin and shrug it off, leaving the heel unsure whether to try to top his own line or just awkwardly make his exit.