// What I can't understand is the sheer arrogance of those wanting to stop a public decision because their views are so much more important than other people's. //
I don't think this is fair at all. Most notably, rescinding Article 50 doesn't of itself mean that we never leave the EU. It just means that we don't leave *now*, and arguably get a second chance to leave properly, if that is the future wish of the nation. The current mess is in part down to deciding to leave before we had worked out how and why, Theresa May in particular, and Parliament with her, deciding that they had no other choice but to start the process as soon as possible, even before it was properly planned and agreed what our route out was going to be. Now, granted, this is surely not the intention of most Remain supporters, who would want us to stay in the EU indefinitely. But it's a point worth making. There is nothing to stop, say, Nigel Farage and his new Brexit Party from winning a general election, and of course they would then have a mandate to restart the whole thing (and, for that matter, a Parliament in relative agreement on how to go about it and why).
Even setting that aside, it is a nonsense to argue that this is about arrogance. Leave voters do not have a monopoly on patriotism. Remain voters care about the UK and want to see the best future for it, just as much as Leave voters claim to. If they feel that the UK's future is not served by this policy, and even is seriously harmed by it, what else do you expect them to do? Why this insistence that they must lie down and allow it to happen? It could be argued that they've already made that mistake once, some not quite taking the referendum in 2016 as seriously as they should have.
So, no. It is not arrogance. Nor is it dismissive of the views of Brexit supporters. It's bizarre to call it immoral, or anti-democratic, to stand up and fight for your future as best you see it.
And, in the end, it's "only" a petition and a protest march. They didn't do anything stupid like deliberately stopping traffic, sending death threats to opponents, or the like.