It's not just about the relationship with Lovie. It's about the HS coach egos, and whatever program strokes their ego the best gets the push for their players. They may like Lovie and even respect him, but when a HS coach making $120K for 180 contact days in Illinois (plus about a $9K coaching stipend) who's pretty much guaranteed about $80K pension at 55 their networking isn't so much about getting college work in sports after retirement. They're pretty much set and don't want the incredible work load of a P5 assistant.
It's about ego and status of their peers. It's about having Harbaugh, Franklin, Fleck and Kelly dropping in and sucking up to you.
Lovie hasn't had a lot of status in Illinois for quite some time now, and him visiting in no big deal. He's just a utility player to Illinois HS coaches, as are many others. They want the status of sending a player to ND, Michigan, Iowa, Wisconsin or Penn State to crow about, and perhaps "recruit" top players to come to his program from other schools. Getting a schollie to Illinois for one of your marginal D1 players is a good HS coach recruiting tool for such players, but he needs to get schollies from the big programs to attract other top prep players. Sunkett at ESL is a prime example of this. Most of his top players could play elsewhere by just renting an apartment in another district if they wished. Being a schollie machine for good preps and getting attention from top college programs is the way the steady stream of stars keep finding their way to his door....
College coaches need to "recruit" the HS coaches as well, and trust me, if a college coach treats them as somehow inferior (hard not too when you're being grossly overpaid at $5 million per year!) they'll blackball generally mediocre programs all day long except for "reaches" not worthy of P5 schollies.
That's why a HC needs to hire top recruiters who already have a relationship with the HS coaches when you're building a program. The assistants bring beanding the program doesn't have. Unsuccessful programs trying to build such relationships starting from scratch is just a recipe for recruiting failure, and that's exactly what Lovie did when coming to Illinois, and why IMHO his prep recruiting has been so substandard to build a competitive program.