Crossfire directly contradicts this statement.I would say the opposite for Odo. He may have made some poor decisions at some points but overall he always had the safety of others on mind.
Again, Crossfire shows that these issues were far more problematic for Odo. His obsession for Kira nearly got Shakar killed, and instead of hunting down the would-be assassin, he hung outside Kira's quarters until he could sulk in front of her. Auberjonois is an amazing actor, and the character is rich and interesting, but he was, at this stage, a classic creep.Bashir was more concerned about his sexual prowess. I still like him a lot but he’s definitely not on my list for most selfless.
And Bashir was never concerned with his prowess. He may have been oversexed, but he never expressed any concern for new sexual conquests or showed any discomfort with being faithful within in a relationship. There were times he imposed himself or pursued a relationship that ought to have remained professional.
Which finally comes to the question of why curing the blight and the Founders' disease was not selfless (as if selfless is the only criteria by which to judge morality)?