Ok, naive rather than liars. However, for people to push for something, and to gain votes from the public, on something so important and complex, if they were naive in their thinking and understanding, I still think that is unforgivable. You expect a certain level of knowledge and intelligence from elected politicians, and for some of them to have failed so badly leaves a bad taste. I agree it would help if the margin of victory was more clear cut, but poll after poll and vote after vote in Parliament shows low 50 and high 40% results. The nation was divided before the ref, and 3 yrs later is still divided around the same margin. If remain had won by a sizeable margin, I don't think many pro leave would have said 'ok all done, lets get behind the Govt and get a better deal from Europe going forward'. Until its 70/30 or even 80/20 then its all to play for, for both sides. Not saying I want that, but there will always be this problem. Whoever invented the idea of a referendum on this (not saying anyone in particular), if they foresaw paralysing this country for years as the end result, I think they have succeeded.
Was that May's deal that ticked the all the boxes? If so, as a withdrawal deal to plug the gap while we negotiate the future trading deal, yep agreed take it. However, some of the most prominent leave politicians were some of the most vocal in their criticism of it. Why? Because it did not square with what they 'naively' promised before and just after the referendum.
The GFA - again not saying good people v bad people. I think your 'naive' label fits the bill. If Dublin has used it as leverage, then I applaud them. We voted to be in this position where these things could be used against us. We were told we had all the leverage in these negotiations (German Cars etc) but as yet I have not seen it. Now that our so called 'leverage' has disappeared, UK politicians are left trying to plead for 'good faith'. Negotiations are tough, and on this scale, even tougher. The aim is for everyone to walk away at the end after shaking hands, but its going to get frosty during it.
As for compromise, I think we will have to agree to disagree. From what i read, we proposed a) rejected, they proposed b) rejected, then a compromise was made. They conceded to UK wide access to the CU, but we conceded to no time limit on the backstop. Eu also offered a bespoke deep CU type relationship which has some aspects of the SM regulations covering only Norther Ireland. This was bespoke and i think one of a kind. This was rejected 3 times by parliament, and again the loudest leave political voices were very anti the deal. Could be that they wanted to cover up their naivety, or maybe they wanted no deal all along. As for the billions, again you and i wont agree. I see that we paid a fee to have access to the CU and SM. We got some of that money back in order to be spent across the country without domestic political allegiances, and businesses as part of one of the larger EU members took full advantage of access to the bigger and wider trading market.