Do these prescriptive advisors know what they are doing wrong and improve their style? OR do they often think they are doing great?
I think one way for them to realise is through situations that put them in a position to seek advice and when prescriptive advice goes wrong for them. This need not be in startups but in any wicked environment. I think that could force many prescriptive advisors to reflect on what they dole out in the form of advice.