I think two completely different hypotheses for this phenomenon are more likely:
Hypothesis #1: It can be a dog whistle between investors that an entrepreneur will “stop at nothing to succeed” which can include borderline unethical behavior. Investors may prefer to invest in companies that act in this way, but the investors don’t want to overtly condone unethical behavior and instead use coded language to avoid personal liability. The poster child of this is probably Travis Kalanick, the CEO of Uber who reportedly had no problems with booking fake rides on competitor’s ride sharing platforms in order to gain an advantage. I bet early Uber investors said stuff like “I had lunch with Travis and we should invest in that guy! He’s so driven, he has such a singular focus to succeed!”
Hypothesis #2: Solving valuable business problems is nowadays extremely difficult, because all the low hanging fruit no longer exist. Therefore, it’s very easy to run out of money before such problems are solved. This means that the payoff for any effort is extremely non-linear, and an all-out attack is far more likely to succeed before any funding dries up. According to this hypothesis, it may paradoxically NOT be beneficial to do an all-out attack if you have enough funding (but typically people don’t have this luxury.) If this hypothesis is true, a person with enough $$ and time may want to “put their eggs in several baskets” and have a greater chance of success through diversification (though it would likely take a longer “clock time” for any project to succeed). Certain types of artists/creators may fall into this zone, and hence many such creative people would probably not benefit from the “all in” approach- I actually developed a productivity system for such people (http://www.lisperati.com/#!A_Productivity_System_For_Creators) which is the antithesis of the “all in” startup mentality.