My 2 or 3 cents:
1. These issues only come into play with elite recruits, and as you get closer to the #1 player in the nation, the value goes up dramatically. If the rumors are true, for example, Drummond was worth $150-$200k as a collegiate signee. No clue if that amount is reliable, but it strikes me about right when you consider what pro and overseas players make, along with the preference of US high schoolers to go the college route. Conversely, it wouldn't surprise me if things are relatively clean/modest outside the top-100.
2. This is a problem that comes up mostly because there's so much money at stake. I say mostly, because even before there was a ton of money in college sports, there were ringers brought in by rich boosters who wanted to win. Consider that Elite coaches make several million each year. Shoe companies have far more at stake. AAU coaches I would expect have a tough road, but at the upper end of AAU, can get enough sponsorship to get by and then occasionally get a payday from the talent that passes through. You put enough money into something, and feeder markets will develop naturally.
3. People and programs who do this have had many decades now to get sophisticated about it. There are lots of convenient layers with AAU, agents, boosters, etc. to insulate the coach. I'm sure some coaches have to do some of the dirty work, but that's a sign that their booster network hasn't "matured" as they say in business.
4. Morally speaking, I personally don't see anything wrong with the people dedicating their lives to youth basketball, or the players themselves, working against the NCAA's desire to take the entire pie. The NCAA has plenty of great PR working on their behalf --non-profit, we give out scholarships, we support non-revenue sports, etc., but the bottom line is that the executives running the collegiate business aren't here for the charity work --they make a TON of money themselves, and answer to presidents of universities who also make good money.
I do think the program was squeaky clean under Weber to the extent Weber had control over it. I also think "clean" is not just in the hands of the head coach, though. For example, I strongly suspect that Izzo wouldn't participate in influencing recruits outside the rules, but people around the program would. Programs just aren't black and white these days, and lots of "influencers" can work independently.