Tall people can have technique, but a coach sees a tall kid and assumes he will keep growing and needs to make sure he is molded into a position he could be useful in. The fact of the matter is most tall people, even if they great technique, do not have the Shifty*bleness and mobility to use it as would be required of them if they were played in the more 'technique-centric' positions like winger and playmaker. Not to mention that while technique is brilliant, physical gifts can be just as good, and making the most of them is important. A tall guy is most effective as a striker or as defender stopping a tall striker (although I expected to see more Fellainis popping up soon), so that's where you're shifted to.
It's why if you're small and fast you're put on the wing or maybe as a striker. And since those are your positions you start developping the skillset required for that position, so small guys develop dribbling and tall guys develop heading and stuff like that. That's why I think the most interesting footballers are those who grew up one position and changed at some point, giving them a different skillset (kind of like all of those converted wingers playing fullbacks).
It's why if you're small and fast you're put on the wing or maybe as a striker. And since those are your positions you start developping the skillset required for that position, so small guys develop dribbling and tall guys develop heading and stuff like that. That's why I think the most interesting footballers are those who grew up one position and changed at some point, giving them a different skillset (kind of like all of those converted wingers playing fullbacks).