What, do you guys think that if we sh1t on him the entire time that Putin would show up? He needs an incentive.

But....we don't care if he shows up, if he's not actually there to bargain.

That's the key. You don't give him the carrot of a head-of-state summit unless and until he's agreed to preconditions necessary to assure that this is an actual negotiation, and not just giving PUtin the carrot for nothing. Typically that involves a lot of discussions and agreements among the various foreign ministers about what is actually on the agenda - and some public statements by the Foreign Ministries about what the agenda is, so that there's some "skin in the game" if the parties decide to yank a topic.

What you describe as "sh!tting" on him is more accurately described as diplomatic isolation. The leaders of the world refuse to engage with Russia at high levels. It's a reminder to his people - and more importantly his bankers and his property owners and lenders and business folks - that there's a diplomatic cost to what he's doing.

You don't give up on that and give him the symbolism of being warmly accepted by the Leader of the Free World in exchange for.....nothing. He showed up to the table with nothing, and never had the slightest intention of giving us anything. And we let him do it.