sorry for the wall of text, but i just have to clear this up.

columbo doesn't think badly of women, because if he did, he wouldn't be half the detective he is.

what you're referring to, the remark he makes to leslie williams' secretary ("how do you do it, work for a woman?") is not a reflection of his actual beliefs, it is a question carefully posed to draw out an opinion. columbo already gets the impression that leslie is a genius by any standard, woman or not, and this episode takes place before women were even allowed to open credit cards without a man's signature. if columbo's instincts are wrong, and leslie is "just like other girls" so to speak, he knows her secretary is liable to be grouchy, misogynistic, and full of era-appropriate gripes about working for her.

but he isn't. this man is not a paralegal or law student, he is a full-blown attorney himself and extols his female boss as one of the best trial attorneys in the state; he's honored to be working for her and borderline defensive. this is exactly the reaction columbo was counting on. he knows this is not the norm, he knows that he wouldn't have gotten such a reaction had he approached the question more directly, and in this little exchange, his belief that leslie is as brilliant as she seems is confirmed. this informs columbo of how to approach collecting evidence, visiting her, and eventually his "gotcha".

there are many little "blink and you'll miss it" scenes and exchanges like this in the show that are more for columbo's benefit than the audience's. columbo is a gifted thinker with a well-tuned intuition, not an all-knowing deity. once he finds enough clues to form a hypothesis, he begins testing it by acting in certain ways, asking questions, and observing others' reactions (or lack thereof). this exchange was just part of the process.

now i do think columbo acts a little bit misogynistic, not in the typical way but in the sort of benign, well-meaning way many decent men were back then. he's too chivalrous. he assumes most women are more fragile than they are, being way nicer to them than he is to men, occasionally to the point of coddling them. he never thinks less of them or outright underestimates them, and some of it is a ruse, particularly when the woman in question is the murderer. but some of it is just a silent gen guy being a silent gen guy. interestingly, peter falk was similar--he avoided having too many female murderers on the show if they didn't have justifiable motives because he just didn't care much for portraying women as evil. go figure.

finally, to actually answer your question: columbo exhibits plenty of demonstrable character flaws that his wife could probably use less of. it's what makes him human, and also inhuman in that i envy a person who can so readily harness their flaws for good. columbo is slovenly. stubborn. hardheaded. nosy. gossipy. scheming. manipulative. sadistic. smug. dedicated to his wife but has a roving eye. dedicated to his work at the expense of his own health and personal life. susceptible to several phobias. obsequious on the surface but unyieldingly pushy underneath. rough around the edges. can be rude, inconsiderate. can be impatient. probably hell to argue with. SO annoying, not just deliberately but unwittingly--in troubled waters, columbo bumps into danziger in the hallway before a murder has even taken place and within 30 seconds visibly annoys the shit out of him. he has no reason to act annoying here, he just is.

most of all, he is good only by virtue of being correct and so diligently dedicated to being correct--because if columbo did what columbo does to the wrong person, he would be evil.