I co-RD'd Grant's Tomb Crit last month with $1k in sponsorship money and a total of $2800 in payouts. We had 382 unique starters and 665 total registrations, with all of our men's novice and cat 4 fields (a 5, a 4/5, a 4, and a 3/4) selling out despite it being a technical 5 corner crit with a selective hill. The total operating expenses was somewhere around $19k, so that $1k in sponsorship money represented ~5% of our overall profits/losses. Similarly, my Bear Mountain Classic circuit race with a descent into a technical hairpin corner that transitions immediately to a climb had similar success, though without any sponsorship support.

Technical course design is not what makes or breaks race registrations, and folks will not improve their skills if not given a space and motivation to do so. I understand how you arrived at your argument but unfortunately it's not represented in actual practice.