Folks here on forum say that most English taught programs in Polish universities are not of high-quality.
That's correct. Most of these programs are a joke and diplomas from them will not help much on the job market, in Poland, in the EU and elsewhere.
Well, at least they are recognized in EU and I cannot be rejected holding Polish diploma, right?
Having a diploma does not guarantee a job. Not by a long shot. The quality and reputation of the program are important to employers, and they can reject you because you diploma is not good enough, even if it is from Poland.
I was planning to major in technical field and get first work experience in Poland right away,
As I said above, this is a very unwise plan. Make your plans assuming that you will NOT get work in Poland.
but I have no idea what my chances of finding a job in Poland are and what salary I can expect to get with no prior work experience.
Chances of finding a job in Poland are poor. Don't count on it. Salaries are also poor, especially for entry level jobs.
are they willing to accept foreigners in the labor market?
Yes, if they are highly educated, highly qualified and very experienced, especially at higher level jobs. Not so much if they are not and applying for entry-level jobs that Poles can do. Generally, you're going to be fiercely competing with masses of unemployed recent graduates from Poland. Unless you're really outstanding, they are going to get hired before you.
Is it a good idea to graduate in Poland or I should consider another European country?
Graduating from an English language program in Poland is probably no better than graduating from a university in the Ukraine. Graduating from a serious program at a serious university in the Ukraine would be worth more on the job market in any EU country. If you want to study anywhere in the EU, make sure it is in a serious program at a serious university. If you study in an inferior program at a low-ranking university, your diploma will probably be worth a lot less than a diploma from a serious program at a serious university in the Ukraine.
So far, you haven't said anything to indicate that studying in your own country is the best option available to you. Without good reasons to study in the EU and a good plan for doing so, it would be unwise to do so. It seems as if you think that any old diploma from any old university in any old EU country is some sort of "magic key". It isn't.