Polish pronunciation is so complicated that it is impossible to write an engine that would pronounce words

Yes, adam - the real problem for English speakers is that familiar-looking letters are used in very unfamiliar ways. Polish is written down using something between the (errm, correct me if I'm wrong here, someone) Cyrilic and (errm) standard Western alphabet.

And quite apart from that, English speakers are hardly consistent within their own alphabet:
http://magazine.englishclub.com/199909.htm
(namaste to good ol' MaxQ for this one!)

Fisk