I agree that any talent shortage is likely to be an upstream problem from hiring.
I don't agree that eliminating a bimodal model is desirable though. We don't really need more people in the middle of the talent trough because they don't actually add much value and can often detract value (in my experience). Successful programming is the grappling with immense complexity. You really only want the best and brightest doing it. As long as the people with the desire and capability are being given the opportunity to enter the field, I think we've succeeded. Trying to lower the bar or get people who wouldn't excel into development would be a mistake though.
I didn't realize I put forth that the bimodal should be eliminated. Just that I don't think it should be taken as a natural fact. It may be that eliminating it is meaningless. It may be that keeping it is meaningless.
Consider, do you really care about having the best and brightest doing something. Or just getting the best results. Odds are high that those align at least somewhat with each other. I don't know if it is a foregone conclusion, though. Study will show.
If you have experience that a normal distribution brings down the top end, I'd be interested in seeing it. If it is just a gut feeling, it is something that can be tested. If it can't be tested...
I wish I had the resources to formally test the hypothesis but alas I don't. However anecdotal my experience is, it has been consistent and enough that I'm not willing to risk my career hiring anyone other than the best I can find. It's actually a lot easier to hire mediocre developers so I wish that produced great results. It hasn't for me though.
I want to be clear that I am not asking you to formally test anything. And, I would extend "you" to the entire industry, at some level. I do not expect companies to try and tease out the reasons for distribution in workplace for most things. Affirmative action not withstanding.
What I do applaud, is research to into the problem. Which begins, largely, but asking the question.
I don't agree that eliminating a bimodal model is desirable though. We don't really need more people in the middle of the talent trough because they don't actually add much value and can often detract value (in my experience). Successful programming is the grappling with immense complexity. You really only want the best and brightest doing it. As long as the people with the desire and capability are being given the opportunity to enter the field, I think we've succeeded. Trying to lower the bar or get people who wouldn't excel into development would be a mistake though.