Who do you think is making those poor protocols and buggy implementations? People who are affected by IPv4 address exhaustion - which is most of the non-US world - know how important IPv6 is and prioritise it. People who aren't affected and don't know anyone who's affected - which is people in the US - don't care (and I don't think this is some deep moral failing - it's normal and natural to not care about an issue that doesn't affect you), treat it as an afterthought, and the poor level of support you see is the result of that.
Businesses are the big holdouts in the US. They have existing complicated networks and address allocations, and don't see the need for an upgrade.
That's already happening on new networks that need a lot of addresses (e.g. most big mobile carriers do this). IPv6 is pretty heavily used, but like most infrastructure you don't notice it until it breaks.
> Businesses are the big holdouts in the US. They have existing complicated networks and address allocations, and don't see the need for an upgrade.
"Businesses" is too broad a category. But fundamentally anyone who has plenty of addresses and isn't feeling the squeeze has no real incentive to upgrade, so why would they.