Some are. The rest aren't irrational so much as impatient. They tend to believe -- correctly or not -- that the winners and losers among their portfolio can be

Some are. The rest aren't irrational so much as impatient. They tend to believe -- correctly or not -- that the winners and losers among their portfolio can be identified quickly, and prioritized accordingly. They are not just thinking about your company in isolation. They are thinking about it in terms of stack-ranked IRR on a spreadsheet with other investments.