The cost a an INFI Hawk is probably one of the major inhibitors.
I know that comparing the cost to a knife is not necessarily accurate because of how you can overlap the cuts in the sheet to make a 'hawk vs. a knife - but...
If you look at a 3/8" (thicker would be even better IMO) piece of INFO that is 18-24" long you are talking well over $1K (based on the current large blades as the comparison). You also may have more fine grinding / work on the Hawk depending on the design that a long, even knife blade.
I would love to see a longer, thicker Busse Hawk - but for the uses I have in mind, I would be more than fine with SR101.