For every person shouting 'how can you vote for Boris the liar?' there are several people looking at the Labour party and quietly wondering 'how can you vote for Jeremy and his disorganised, economically illiterate Marxists, who can't even formulate a coherent policy on one of the biggest issues ever in British politics?' See also the '251 employees' debacle for an idea of the level of thought which had gone into the Labour manifesto.
Meanwhile, Boris clears the Remainers from his party, giving the Conservatives a clear direction on Brexit. Now, there is no such thing as 'No deal', because even if we leave without a deal in place, the EU are major trading partners, so of course we will strike a deal with them. However, even people who haven't worked that out are inclined to back him.
Back at Labour Towers (or Twitter, as it's also known) Labour supporters, shouting into their echo chamber, are convinced they're going to win, clearly disregarding every poll. There were such hashtags as 'youthquake' and other blindly optimistic nonsense. I even saw one tweet circulating where a breathless leftie claimed to have have heard the Boris Johnson was 'in trouble' in his own constituency; Boris was eventually returned with 53% of the total vote and 10 seconds' research would have shown that this was always going to be the case.
Whatever your political views, Boris tactically annihilated Jeremy; now, with a whacking majority, he just needs to be clever with the introduction of popular 'one nation' policies; he has the opportunity to improve the outlook for the nation (and keep Labour out of power for a generation.)
Back at Twitter, Labour supporters are incoherently bemoaning their defeat, calling all Tories rude words often beginning with 'C' and completely missing the point that they were totally outplayed. Meanwhile, Diane Abbott turned up to vote wearing two mismatched left shoes. It's certainly the sort of gaffe which leads people to suggest that you're not fit to govern*.
In short, to lose against a party which had been in such a mess under Theresa May such a short time ago takes spectacular incompetence.
* It's also the sort of thing someone with early dementia might do; I genuinely hope she is in receipt of a thorough check-up.