It's ok to change your criteria in mid-discussion...LOL.
Nobody in their right mind going to dismiss the value of a West Point education and networking opportunities. You made the initial point to sound as if it was unique in those qualities, as a selling point to the undecided OP.
My point is that there are, indeed, other strong networks besides that of USMA, if that is a consideration for one's future.
I've had this very discussion with our DS, in that, if you happen to go on to serve 20 years as an officer, and upon retirement you go after other opportunities- do you really think where you went to college is going to outweigh your performance as a professional leader of military men and women?
Considering I never discussed any criteria to begin with, I fail to see how I could "change" my criteria. Are there alumni networks at many schools? Yes. Heck, my wife is a member of the Yale Med alumni network. I throw their rag magazine away every month. No one is doubting their existence. My point is that the old grad network or "Ringknocker Mafia" is legendary for their lifelong commitment to graduates.
Their existence doesn't mean they're equal. There's nothing wrong with what they are, at all. My parents are Ohio State alums and the "O-H I-O" alumni brand is very strong. They bleed scarlet and gray. At the end of the day, though, the ties you find among WP grads (and USNA and USAFA and probably the CGA as well) and the network those ties have built is something you simply won't find to the same degree elsewhere, with perhaps the notable exception of SMCs like VMI, El Cid, and maybe Norwich (I'm not terribly familiar with Norwich as an institution).
Your point about what will "matter" after 20 years is not without merit. Not everyone does 20 years, though. Some people do 5. Some people THINK they want to do 5 and do 20. Many also think they want to do 20 and do 5. When you decide to get out at year 5 and want to get an MBA, West Point opens a lot of great doors and instantly puts you on the radar.
As far as "don't go to WP if you aren't sure because someone else wants it more and they deserve it as much." No, they don't deserve it as much. If they did, it would be THEIR slot to give up and not his. Secondly, anyone who tells you that you have to be "sure" is just plain full of it, and probably a little bitter and jaded.
I often tell candidates that before R-day I wasn't sure about West Point. On R-day, I was sure I wanted to go anywhere else. I got to be pretty sure I'd made a huge mistake. My buddy was sure it was for him and that his life's calling was to be in the Army. He quit plebe year. I'm going on year 8 in the Army.
It doesn't matter how you start. It's how you finish.