Upvoted for the term clustercuddle. A couple of points:

1) It's probably not unusual to have $150 million in value tied up on the success or failure of a beta.

2) Calling this "beta" was a stretch. I'm of the opinion that the first "beta" should almost always still be called an "alpha" until in-the-wild bug fixes. However, it would be difficult to get $150 million invested on alpha software. It may have been beta for etherium, but it was definitely alpha of DAO.

Maybe it's not an excuse, but it seems like a reasonable explanation. The system clearly isn't ready to handle $150 million but some folks did it anyway.