Politicians don't join the governmet to work on personal projects. They directly impact government projects. In a setting where they are to be voted, it makes total sense for them to share their opinions on how government peojects should be run, or how government resources should be distributed. Otherwise if a politician decides to use their personal income to build a community project during campaigns, the voters tend to say, "where has he been all along, he is not helping us, rather he only wants us for our votes". Should every individual with the chance to lead invest recognizably in the community as they can run for a political position anytime? This is simply impractical. If a democracy is to chose a leader, let it know how he will use the existing government projects, what he has contributed to the existing government projects, perhaps in their previous position, then the democracy will know whom to expect results from.