I'm in the camp that thinks no deals is a good thing.
One reason being as noted, almost everyone would deal. It would become an expectation to deal, and people would "get screwed" when there was a random player who "wont's million" at the table. There would be regs making witch hunting forum posts, Xx_assssdf_xX is a "non-dealer", treat him like the scum that he is! Pretty soon it would be the norm to chop everything down to 100x, maybe even lower - unless there was a fish, of course - in which case, soft-collude, bust him then chop. A horrible environment.
Are people thinking the deals would only ever be 33% 3 ways? I don't see why they would be - and then you have the battle of bankrolls (more like life circumstances). you'll get "I'll deal, for half a mil. hope guaranteed $300k vs likely $100k isn't a massive difference to you regs".
The variance is what brings in the punters. Never forget this basic rule of the game.
Ironically, the "deal" people are arguing for a more lottery-style setup. Taken to the extreme, where they deal in every single game - there is no poker any more, just put in $$$ -> see what the spin wheel gives back. Of course nobody wants this, and if they do slots are available just one tab over - but technically, that's what you're requesting - "more slot machine in my spin&go please!"
"No deal" - is advertised, and heavily. Every single table of every PS spin&go has "Deal Making Unavailable" written big right in the center of the table. You're unlikely to find a player that doesn't know deal making is unavailable in spins. You may not consider this advertising? If it said instead "Enjoy Coca Cola", I think it's pretty obvious
There is a deal already, automated and enforced fairly for everyone. 8% split evenly, play for the rest. Nobody ever really gets screwed spinning a million.
Probably a bit incoherent, lol