I don't know for sure, but I'm guessing that the nation itself is - certainly at the moment - very much either Left or Right and those of us 'in the middle' who would be happy with a coalition, are a minority.
That's the impression I'm getting from SM sites.
We're not schooled in coalition government, it's not part of our tradition (apart, obviously, from the devolved governments).
I think it's sort of the usual, done-thing, for parties to play down the possibility of a coalition ahead of an election. In 2010, it was assumed that a Conservative - Liberal coalition was "highly unlikely", and one of the Lib-Dems was supposed to have insisted that they'd find it nigh on impossible to be part of a Conservative led coalition - or words to that effect. But - it happened!
If the recent local elections turn out to have been the usual "bloody nose" voting, and, come a GE, voters return back to their fold, it's not impossible that the Conservatives would again win, but without an overall majority. But I can't see how they could form a coalition with the other parties now - because of Brexit.
The current Conservative party's reign is though, I believe, over. I know there is a faction that believe 'bringing back Boris' will restore their fortunes, but I believe, and hope, they are mistaken. Brexit is "done" (in the sense that Johnson wanted it over and done with and out of the way) so goodness only knows what 'ticket' he'd ride back in on. Even Rees-Mogg acknowledged that “If we’re a grown-up party we cannot change leader again between now and an election.” As Tobias Ellwood said, "bombastic populism may rally a small base but does not appeal to the wider electorate whose support is needed to win elections.”
But, I've reached that age / stage where nothing much surprises me anymore, so...