the thing with Dream is that his character is so... fascinating, that the possibilities with him are more vast than with basically anyone else on NXT. in some ways, he's similar to Goldust, who could pretty much be included into any role and do a great job - but Velveteen is younger and has a better look.
with guys like Gargano or Ciampa, can you really do something with them on the main roster? they already told basically everything that could be told, turned both of them heels after making them feud with each other