One of the best episodes of season 7.
One of the show's best, and therefore one of Trek's best as far as the depth of the writing is concerned. There's a lot to be said about it, but I guess I'll just address the topic of the op for the moment. I will say in passing, though, that Laas is not written to inspire sympathy: that is why he blatantly acts like a dick to everyone on the station

However, while he is unsympathetic, or at least not admirable in his contempt for "humanoids," he is also largely correct in his perception that Odo does not feel he can be himself around his "so-called friends." Therein lies the problem: Odo would like to believe, as we would like to believe, that Laas is wrong and just acting like an a-hole, or just bitter due to his own bad experiences, but the closer Odo looks at his own life, the less he can be sure.
As for the op, the "Each Season's Worst" topic comes up every once in awhile. Mostly there are one or two obvious choices in each season.
For season one, I usually go with
Q-Less. It's a RHW script and, while I get that he was trying to highlight the differences between the DS9 crew and the TNG crew, there's just nothing entertaining about this episode other than the spectacle of Sisko punching Q. This should have been kept as a DVD extra, while the rest was deleted. The differences between the two crews' personalities and interactions are obvious and are actually clearer in
all the other season one episodes.
The Passenger and
If Wishes Were Horses are also understandable choices, however.
With season two the choice is much more difficult as nothing really scrapes the bottom of the barrell imo. I go with
Rivals, as it bored me the most by a wide margin during a recent rewatch of this season.
With season three, the choices start to become a lot more obvious. It's
Meridian or
Fascination, hands down, though Ferengi-haters could probably make a case for
Family Business due to the cringe-inducing scene where Moogie gets naked and caresses Rom.
Season four:
The Muse, I don't think anything else even comes close in what is probably DS9's most consistent season, though not its best.
Season five:
Let He Who is Without Sin... is another easy choice. The only real competition is
Ferengi Love Songs. This is one of the best seasons in all of sci-fi/fantasy.
Season six:
Profit and Lace.
Season seven:
Extreme Measures, because it should have been great and wasn't.
The Emporer's New Cloak is probably worse, but since it doesn't happen in the middle of the final arc I tend to notice it less.