If people don’t vote, then the result will always be an unpopular one, upsetting someone… Like McCluskey’s win on a sub-20% turnout upset just about everyone in the country not in a union at all! 
More effort needs to be made by politicians of all parties to “get the vote out” - even if it ends up being “against those most asking for that”.
Imagine if Corbyn had won on 40% instead of losing with more popular vote than Blair got in 2005…