"Seems like a fad, something that only works for Miami."
I've heard this quote a bit in response to preseason stories regarding the small-ball Heat turning the league upside down. The idea is that tradition should hold that "small ball" isn't a workable solution for the future.
I would hazard that those who claim "fad" don't know what time it is. The old notions of point guard, shooting guard, small forward, power forward and center are falling by the wayside because there's no intrinsic need for them.
Back in the old days, basketball positions made more sense. Due to the illegal-defense rule (a rule that prevented zone defense from being played), offense was mostly a one-on-one isolation basketball affair. This was fantastic for big men, who could catch and operate in the post without much harassment. Hakeem Olajuwon was a legend and a genius, but notice how much space he has in this highlight compilation.
Even when Dream gets doubled, it's easy to read. This is because rules dictated that an entire defense couldn't shift to compensate for a double-team. If you were to rush towards a center as an extra defender, your man had to be wide open. Watch a game from the '90s and you'll notice ridiculous-looking double-teams, where someone like John Starks has to sprint back 15 feet to his original marker.
The death of illegal defense also meant that teams could "front" a bigger post player, making post play less effective. Teams today—and Miami in particular—swarm a big man with athletes, blocking opportunities for entry passes. This simply was not allowed back when every team had a low-post power forward and center.
These measures that made post play more difficult also reduced the importance of the center position. If throwing it down into the post isn't the option it once was, there's less of a reason for every team to have a stereotypical "center."
Big men can no longer make unperturbed, slow post moves, so this shifts the game back to the next most efficient option: the three-pointer. The game is now about getting open threes and stretching the defense thin with the threat of open threes.
Shooters spread the floor, opening up space for slashers. Neither kind of player is typically a lumbering frontcourt lug.
Big men will still remain important and height will always be an advantage when everything is equal. But when you look at the rule changes (legalizing zone defense, banning the hand-check, calling more touch fouls), it's easy to conclude that this is the logical evolution of the league.
"Small ball" is here to stay so long as the rules remain like this. Modern pro basketball rewards shooting and speed. From the looks of it, this will continue to be the case.