I think the reason Guardian crosswords get so many comments on 15squared is because they are freely available online. I remember once the puzzle section of the Guardian website wasn't working properly and people were moaning they couldn't get their daily crossword. Did it occur to them to go out and buy the newspaper instead?
Having said that I detect a very occasional left-wing bias on 15squared - the odd dig at Trump, the referendum or election result. But I never understand why the Inquisitor gets noticeably more comments than the EV. Maybe there is a prejudice against the Telegraph.
I was in brief correspondence with the editor of the EV a few years ago. I said I didn't enter any more because I'd won three times already. But he urged me to keep on submitting because they didn't get many entries and he wanted to prove that there was plenty of interest in it.
So we should do at least two things. Comment on 15squared and enter for a prize.