No, I dont believe bitcoin will make alts useless. Maybe you are actually referring to it impeding the price invrease in alts? That would be different than making them useless. As ive seen mentioned already, there are soooo many alts with real USEFUL application, not just a money alternative or substitute like bitcoin. If price depends on demand then the team behind the project just needs to follow through with the initial idea and for it to work and again, be useful so that people will want/demand it. Dont see why alts couldnt grow like bitcoin given time for people to learn about them first and find out they want to use it.