Some people believe that entering politics "dirties" a person since some politicians are corrupt or self serving. People like that tend to believe that private enterprise is somehow more wholesome or honorable.

That's quite clearly not the only reason (and I'm be surprised if it was the majority reason in Europe) that people object to "career" politicians.

The other, reason I've heard is that people who have not worked in industry (at any level) do not have real world experience required to guide policy effectively, and means they are out of touch with voters in general.

Guiding policy is a rather small part of being a politician and usually something (at least in the US) that is dealt with partially by aides. Being a politician in a democracy is about winning elections and forming consensus in democratic bodies once elected. Being in industry doesn't necessarily prepare one to have those skills - example left to the reader.

Which is mighty hilarious, in 2018 :)