Who said acquiring prospects is the only part of creating a team? There's way more to but it's a pretty important part though(maybe the most important).
See how the teams that are in the conference finals are built.
Tampa-
Drafted- Stamkos, Killorn, Palat, Kucherov, Paquette, Namestnikov, Drouin, Hedman, Nesterov, Barberio, Vasilevsky
Undrafted free agents- Johnson, JT Brown, Sustr
UFA- Filppula, Boyle, Stralman, Carle, Morrow, Marchessault
Traded for- Callahan, Garrison, Bishop, Coburn
NYR-
Drafted-Lundqvist, Kreider, Stepan, Hagelin, Miller, Staal, Fast
Undrafted free agents- Girardi, Talbot
UFA- Boyle, Hayes, Moore, Glass
Traded for- Nash, Mcdonagh(acquired by trading a proven player for a prospect), Brassard, Yandle, Klein, St.Louis, Sheppard
Anaheim-
Drafted- Getzlaf, Perry, Beleskey, Palmieri, Rakell, Etem, Lindholm, Fowler, Vatanen, Andersen, Gibson, Etem
Traded for- Maroon, Silfverberg, Cogliano, Thompson, Beauchimin, Kesler, Sekac, Despres, Wisniewski
UFA- Stoner
Chicago-
Drafted- Saad, Toews, Bickell, Kane, Teravainen, Kruger, Shaw, Keith, Hjalmarsson, Seabrook, Crawford
Traded for- Sharp, Desjardins, Oduya, Vermette, Rundblad, Timonen
UFA- Hossa, Richards
So those 'shiny' prospects do matter because you need a lot of them to turn out and even if you look at the trades you see those young guys going the other way so it is very important to have a good collection of them both for your roster and to acquire pieces you need through trade because from the above it shows that drafting and trades are the most important. Not sure why some of you just scoff at it or don't understand why people see the need to acquire them. The very foundation of your team is built through acquiring these young guys whether its by draft, trades, or some undrafted free agent, it forms the base.