Interesting. Im wondering why he was so late. He was pretty much aware of cryptocurrencies for a long time, I remember he was tweeting about bitcoin last year. Was he too afraid to buy below 10k when it was dumping?/
It's that part of psychology where even if they knew about it years ago, it was too small to pay attention to. Besides, he was busy making electric cars and rocket ships. Now that they've got some cash in their treasury that they are not using at the moment (and probably don't need to), they just put it into bitcoin.
It's relatively safer now. If you had a billion dollars 10 years ago, would you put it into bitcoin? Probably not. It would have been a gamble then, but one that we now know would have made excellent returns.
Saylor himself saw bitcoin as early as 2013 but completely forgot about it and rediscovered it only last year or so. These things take time. Some "legendary investors" have got it all completely wrong, they simply just do not understand it yet. Some never will.
For those of us that do, it is still early times.