Potential Solution: MPs should serve for a limited period
MPs can put a career in parliament above making judgement calls that they believe in, that might be unpopular with the electorate or their party.
Making the MP overly concerned with their electability moves us closer to being a direct democracy, than a representative one.
So maybe limit the length of an MPs career to 2 or 3 parliaments, there would then be no career to protect. Support MPs returning to the workplace after serving if necessary.