Theresa May has perhaps gambled on the country preferring to "just get on with it" rather than either backing out or crashing out. In that respect she is probably not nearly so foolish as you think:
https://d25d2506sfb94s.cloudfront.net/cumulus_uploads/document/5v5qj2t7c8/PVResults_181214_Brexit_w.pdf
I posted about this poll yesterday (https://www.theanswerbank.co.uk/ChatterBank/Question1636964.html -- in a correction to my posts then, it turns out that in this particular poll "Leave No Deal" was left off the options, and I apologise for that error): the main summary is that, in a battle between remaining and this deal, the country is split roughly 60:40 in favour of remaining (excluding don't know/won't vote), whereas the Tories are split roughly 3:1 in favour of the deal. Whether that is because Tory voters, or a large majority of them, are "fools", or are just keen to put Brexit behind us in one form or another and move on, I can't say -- and, of course, the situation may change again if "No Deal" is put back on the agenda as it wasn't in the poll above.
I wish I could understand what May was up to, though. At the moment she is serving neither Leavers' nor Remainers' interests, and instead seems to be relying on brinkmanship to force the issue.