I'd like someone to prove that Player X is more streaky than Player Y (provided they score at relatively similar rates) over a large sample size.
Well sure, make a sample big enough and it'll camouflage streakiness more and more. Consistency of play is one of the things that can evolve over a player's career.
That said, I made no claims with regard to this, rather that it's the scoring that makes the streak, not the non scoring. A player has to show the ability to score a lot to be considered streaky; a plug that rarely ever scores will not be considered streaky.