Foreign workers know the pay here is much better than in their native country so it's worth more to them than it is to a UK native. Also they've probably had difficulty earning a good standard of living in their native country so have developed an acceptance of working hard to try to improve their life. Whilst we're one of the countries that has achieved an expectation of a higher quality of life, and so feel work ought not to be such a large portion of it; reducing it so that family and self time is a greater portion.
I think it too easy to blame UK workers for not wanting to accept any position, working environment, or wage. Or claim their refusal to do so is the cause of bringing in those willing to do so from abroad. We have a national labour market, one should let it work well, subject to minimum standards, not allow companies to short circuit it.