One of the huge issues I see is experienced (at least a subset "prestige") investors have the terms best suited to startups succeeding.
I've seen less experienced investors have draconian (almost nonsense) terms -- crazy terms that probably hurt their investments considerably. However, these investors are less accustomed to managing risk in a technology startup.
This is much, much less common in the SFBA ecosystem. However, if you look globally the startup investor maturity can be really poor.