Because the standards, as yet, are incomplete.
So far just the protocol and the USB implementation are there.
There is, for instance, no MIDI 2 file specification.
You can't recode a sequencer (DAW) unless you know how the messages need to be stored.
I don't recall reading anything that says that Steinberg's VST specification has been updated to include MIDI 2 messages either.
Standards as important as these take their time to define and implement, just like telecom ones.
It's quite possible that many manufacturers have deemed that the new messages are too complex for most commercial products.
They may end up only in top end devices.
It's a massive job too, to rewrite thousands of lines of code to incorporate all the changes.