The point here isn't "it can't change someone's life", of course it can. The point is there are lots of people for whom it wouldn't do so, and for those people it legitimately isn't life-changing. e.g., a lot of people would lock that money away for retirement and avoid factoring it into major life decisions at the present. Of course, there are also people who would spend a billion dollars immediately (and even those who would then go broke again). YMMV.
Not at all true. Unspent money is potential energy. It dramatically alters the holder's perception of risks, and thus influences major life decisions.