Re: Stating the obvious
It's very simple. BoJo won an election*. There were sufficient people who did not, at least at that time, find him embarassing and voted for the party of which he was (and, at time of writing, still is) leader and hence prospective PM. They found him acceptable.
OK, I'm making an assumption here: that the intersect of people who found him embarassing and people who voted for him is a small one. The intersect of people who voted for him but currently find him an embarassment might well be larger.
OTOH many of those who did not vote for him found him an embarassment then and still do now. Unfortunately there were insufficient of us to keep him out but we do not find him acceptable.
* Technically his party won the election but the UK system is that the leader of the party which wins most seats has first dibs at forming a government. The leadership of the parties appears to be a substantial factor in determining the way votes go.