I've never said that XBOX was an amazing 1st time achievement...I don't think anyone can in all seriousness. Still, the situations you just referenced had something in common: a softness in the market and an example of working at making something a success in considerably softer competition.
For the NES, its challenge was the state of the market at its release. It's competition was weak...no, extremely weak...which was to its advantage. For the PS1, Nintendo and Sega both could have presented a good challenge up front to stem any sort of momentum, but obviously that was not the case in the early going. That allowed Sony to have a relatively easier time of it.
With the XBOX, the weakness of its two competitors was (and is) not of the same level that would have helped facilitate the kind of nice opportunity that both the NES and PS1 could take advantage of in their debuts. In other words, MS didn't have the luck of their main competition fucking themselves up a bit to allow for an easier, more immediately successful entry into the market...and their goes the subsequent advantage of momentum that can be had from that. MS' success, thus far, with the XBOX can be, IMO, mostly traced to their quick read and reaction of the market, as well as the ususal amount of luck that is always involved somehow. Their massive piles of money couldn't save them if they didn't make the decisions they've up 'til now.