Maybe they just don't want to have to take graduate-level classes in category theory to get their job done.
If I wanted to purchase a large, complex, and unique, physical system (like a new bridge, say), you can be sure that I would employ an engineer who had taken graduate classes on all sorts of technical stuff related to bridge-building. Why should I accept that large, complex, and unique software systems should be built by non-experts, who shy away from education that could help them "get their job done" better? I imagine that if bridge-designers could insert a legal clause in their contract stating "THIS BRIDGE IS ACCEPTED AS IS, WITHOUT ANY WARRANTY..." then we might see fewer engineers bothering to take graduate classes as well. There is a myth that software is easy, and anything that seems to make it more difficult can be brushed off. But what if in fact the difficulties are inherent? Then tools that reveal the difficulty (and help to tame it) should be welcomed. Regards, Malcolm