That is not actually true Keith.
The original Obamacare Bill was indeed completely written behind closed doors with only Democrats and industry lobbyists allowed into the rooms. Once it was written there was some discussion with Republicans concerning amendments, but even that was sparse until Kennedy died and they lost their super majority. Only then did Obama have his public show to try and bring in Republicans because he no longer had the votes to go around them.
Yes a few insignificant amendments were added that Republicans offered, but nothing of substance was added, and it was not Republicans who killed the single payer option, it was the Blue Dog Democrats who killed it and they took a lot of harassment for doing so.
Obamacare is a mess, yes a few “winners” get massive Government subsidies to buy artificially inflated cost insurance policies, but the vast majority of Americans were hurt by Obamacare and the main people it was supposed to help, those sickly people who could not buy insurance, their exchanges were dying off long before Trump came to office and if Republicans do nothing at all, those exchanges will collapse under their own weight in 3 years, is that what you prefer?
Good intentions do not equal good results. I admit Democrats had tried to do a good thing, but they failed.