I think the space-elevator concept is sort of silly, but this doesn't seem like the most pertinent criticism to me. Presumably in a hypothetical future in which a space elevator is under serious consideration, vastly greater resources are being devoted to space technology, launch costs are much less than now, and are about to get cheaper still due to the elevator in question. It seems like if we were on the cusp of being able to 100x the number of satellites or whatever, sacrificing the existing fleet for new ones in different orbits that avoided the elevator wouldn't be too big a sacrifice.