Should dress code be followed properly?

You may think that discrimination, but you're wrong about what men have to wear when they are required to wear "business attire." A man wearing even an off-the-rack suit is wearing a far more expensive outfit than a woman. A suit, with an oxford shirt, a tie, dress stockings and shoes is far more expensive than the business suits that women wear. There is discrimination going on here, but you have failed to correctly identify it.

and while the men have to wear their expensive suits no matter how hot it is, we women can put on a thin sleeveless dress. Again discrimination against men.

Social interaction involves "convergence" i.e conformity to group norms. The fact that group allegiences can conflict needs to be weighed against the practicalities of the immediate situation....when in Rome etc.

I think Mirror is on a different track. It's more a matter of whether women should be able to get away with, say, a pant suit instead of skirt. That's my guess, anyway, and it seems like around here they can and do.

Men do not have the option (realistically) of wearing skirts and large, frilly bows at the neck.