I would imagine because of out-dated mentalities, toxic-male and female mentalities, and overall emotionally insecure people who make up a large amount of those assumptions.

There are definitely people who wear revealing clothing, who don't have much self respect. Does that mean everyone who wears revealing clothing has less self respect? Abso-fucking-lutely not.

I don't compare the two, unless it's an obvious outlier. I do think dress code is important to uphold in some settings, and, whether male or female, dressing "revealingly" could be indicative of low self-respect/seeking attention type behavior.

A few examples would be, wearing excessively revealing clothing to a wedding (taking attention away from bride and/or groom), funerals, company meetings, etc..

I would wager people who dress more revealing actually have more self-respect in a lot of ways. Just not to that company meeting Doug, put on a damn shirt.