Its not so black and white as the politicians and media say it is, they’re all play-acting in their own grand production, and the media are lapping it up.
The MP’s aren’t silenced, they’ve had years to debate an EU exit referendum, a year or more to debate the law allowing the 2016 referendum (which they duly passed) and 3 years to debate what sort of Brexit we should settle for. They could have already passed a law forbidding any PM from accepting a no-deal Brexit: they could have done this any time in the last 3 years but even before that, in fact ever since we joined the EU 40 years ago.
When Parliament re-opens, the MP’s will have enough time to debate Brexit, apply a vote of no confidence and pass a law forbidding no-deal if they can get a majority. It can take about 4 days to get a law passed, but less if there’s a national emergency.
The PM isn’t appointed by the electorate but that’s pretty common round the world. Well, its common where folks have a vote of course.