I would argue that it comes down to how the most popular clients will set their relays. Right now most clients do not actively engage you to set your own relays or choose some from a list. Instead they mostly seem to use some predefined list. If they don't change this then inherently the relays defined by the most popular clients will see the biggest engagement and therefore become the biggest centralized hot spots.

On the other hand i can also understand that the experience may not be really awesome if you pick some (random) relays that people are just testing out for a couple of days or weeks just to see them disappear shortly thereafter.