You said 'mainly to do with internal Tory politics' it was not, it was due to the entire political establishment being scared of the rise of UKIP, they won the 2014 EU election, they got more votes than any other party.
Not in Scotland: here they came 4th, partly due to the Lib-Dems doing badly (as punishment for getting into bed with the Tories), though sadly that was enough votes for them to get them one seat thanks to the PR method used (the odious Coburn, who has since left UKIP). UKIP were more of a threat in England & Wales than they ever were here in Scotland.
Their plans are being made into a clusterfuck because Parliament is doing everything it can to not leave.
I think the whole thing has been a mess from the outset, possibly because the result was unexpected, where even 2 plus years later those advocating it are still arguing among themselves. As such, and looking at the ongoing shambles, as I see no surprise that some are looking askance at how anyone could still think Brexit was a good idea.
Made toxic but three sides, remain, leave with deal, leave with no deal, it is a three way split. If you want to end the mess tell remain to vote for May's deal, that will end the mess, they should stand down since remain lost.
May's deal looks doomed as things stand, where even sufficient numbers in her own party will vote against it so that it fails. Looking at the general chaos I'd say the best option would be to just pull the plug on this now that there is the Article 50 option. If May's deal can't get approval and parliament decide against revoking Article 50 then a 2nd referendum seems essential, and I think the options are Remain, May's Deal and No Deal - and unlike last time make the result binding on Parliament, which should help concentrate the minds of the electorate.