http://www.gamespot.com/articles/sony-explains-why-playstation-vita-has-come-up-short/1100-6417101/
"In all honesty, higher sales would have been what we had hoped for," Sony UK managing director Fergal Gara told VG247. "The market Vita entered was more complicated than it was when the console was originally thought about and designed. Games on tablets and phones have changed the marketplace and people can't carry too many things around at one time."
"The truth is that the number of people that want the core experience [that Vita offers] is not as big as the number that simply want any sort of game available on the move and, because the likes of a tablet and smartphone are so multifunctional in their use, they will always be very appealing," he added.