This statement is near to being tautological. The central test is rather whether people who do "highly innovative things" become more productive in doing so not just by the mere fact that the AI removes some yak shaving from their work.
Otherwise, you could simply argue that people who do "highly innovative things" also find
- a housecleaner
- a personal secretary
- using a word processing program instead of a typewriter
- a washing machine
- an automatic dishwasher
- ...
to be useful.
I'm not actually sure what argument you're making, though? It seems like you're saying that only a certain kind of technological innovation would count for some purpose, but I don't know what purpose you're interested in.
You can read my argument at https://news.ycombinator.com/item?id=36937368
In my answer to your answer (https://news.ycombinator.com/item?id=36937760), I argued that the fact that people doing innovative things often find their machines useful says nothing about that AIs are capable of doing innovative things.