The only way this would constitute a "blocker" is if they actively prevented every one else from using the same connector due to patents etc... I don't know whether that was the case, but simply "not wanting to change their connector" doesn't mean they are blocking progress. They were the first to roll out massive charging infrastructure. I would say it was silly of the other manufacturers to not standardize on what was already there.
Their patent sharing terms say that they get rights beyond patents or copyright: if you use their patents you agree not to copy any of their "designs," a vague term that no one can really be sure of how expansive it is.
You misunderstand: (at least some of) Tesla's patents are likely enforcable. It's the terms under which they can be used in the "patent sharing agreement" which are vague and quite expansive (which is quite possible to enforce in contract/licensing law, and the courts are willing to take very extreme positions on in business to business cases), and that is why no-one has engaged with it.
> I would say it was silly of the other manufacturers to not standardize on what was already there.
it seems silly right now, but letting your competitor own a platform for which your business depends is folly, unless there's regulation on that platform.