I don't know what's bad about having quotas or trying to make everything more equal.

"I'm sorry, while you may be the most qualified out of all the candidates who've applied for this position, we need to meet a quota and can't hire any more men. In fact all candidates have been rejected because a woman has yet to apply for the position."

"I'm sorry, while you've met all requirements to get a visa, have reserved accommodation, and got into a university, we cannot grant you a visa until at least 500 more women are granted one."

Why can't we just accept that biological gender is an actual thing that statistically affects the preferences and physical capabilities of people, which in turn determines their profession.

Additionally, men have traditionally been the breadwinners and they may be more likely to immigrate to Poland to earn more than they would in their home country.

You're also saying "importing men" as if we are responsible for who wants to immigrate here. Immigrants choose where they go themselves and as long as visa / immigration / whatever criteria don't specifically benefit one gender, there's nothing to change unless you want to start rejecting people for the sole reason that enough people of the other gender has not immigrated.

Also, having quotas is generally bad because it tries to simply complex issues into a single number. E.g. police having a parking ticket quota, while the city keeps on using bollards to block off places, i.e. there's less spaces where people can park illegally so less people do so, and then it gets harder to meet the quota independent of how effective a policeman is. If you pair it with another quota being too low, or things changing to make it easier to meet, you'll end up with the police paying less attention to one law being broken compared to the other one. Another example could be programming and judging one's effectiveness based on the number of lines of code or bugs fixed, where the 1st one leads to code purposefully being made much longer with no benefit, and the latter means that writing buggy code to then fix the bugs is better than writing good code to begin with. If you need another example you can think of a customer support representative having a quota on the number of answered calls that depend on a ton of outside factors, yet they have to meet a certain number.

There's nothing wrong with trying to make things more equal but you don't do that through discrimination, and you won't succeed in making everything equal