it seems these suggestions work better with their particular niche (B2B health care, security, etc). Don't think it works well with all investors. I would take it with a grain of salt
With respect to TAM calculations and competitive positioning. What if you introduce a first to market product in a target market that is an emerging space like cannabis or an underdeveloped function of E-commerce like Alcohol sales and there is very little in the way of comparable history (whew)! How does this affect a bottom up TAM calculation?
Absolutely! Talk with the ones who work in a corporate environment, observe, learn about their problems, ask and listen,... There is no "must" prerequisite.