The academics you want most for consulting are the ones from research universities. However, those academics generally work 80 hours weeks already just to keep their jobs.
I know this first hand. I was a postdoc at a major research university, at the time intending to follow the academic career track. This was after doing my PhD at another - albeit much smaller and less prestigious - public research university. What I saw as a postdoc while rubbing elbows with junior faculty really opened my eyes.
Junior faculty at major public research universities are working at least 80 hours a week. 40 hours go to grant writing, lab management, and departmental obligations. Another 20 goes to teaching. 10 goes to managing institutional requirements (including negotiations for how much they pay to their institution for space, utilities, etc - and consumption of those resources). Another 5 goes in to actual research. The last 5 goes to attending local seminars.
When a most junior (assistant professor) faculty member makes it to the next level they are still working 80 hours, but they're making slightly more money. Now they are putting more effort into making their pitch for tenure (if it exists at their institution), or looking at where they want to work next (if that's a better career path for them). If they ever make it from medium level (associate professor) to senior (professor) - and many never do - they still need work 80 hours a week but now they have a larger presence on campus.
At what time do we expect American faculty to have more time available for this?