Well, first of all, you ask for the impossible.
Imagine they really ban those barcode nicknames. You think the players will immediately go and pick all the different nicknames? No! They will just use some other characters, like “LLLLLLLLLLLL” or “UUUUUUUUUUUU”.
Even if Blizz makes it impossible to use the nickname already used by someone else (which I’d gladly accept, sick and tired of those countless “Alex” guys), the barcode users will just combine characters like “|||I|l|||l||” or “||||||l|||I|” — combinations here are countless. There’s just no possible way to prevent all this.
Second, you’re missing the point about the game stagnation reasons. This game stagnates first and foremost due to the lack of new players — they don’t care for barcodes, they might not even care about the ladder overall, but they do care about the new content, which goes in campaigns, co-op, arcade etc. So no wonder that Activision’s greedy strategy “make as little new as possible, reuse old as much as can” leads to these tragic consequences.
Third, how in tarnation can the barcode nickname decrease streamer’s view count? Just… how?? People watch the SC2 streams to see the gameplay, the nicknames of opponents mean little for them. As for the barcode by the streamer himself, this makes even less sense, since stream viewers actually know who is streaming by seeing Twitch/YouTube nickname and often streamer’s face on webcam too — do you really think that won’t be enough for them and that they should care about the streamer’s ingame nickname?
And fourth, you may think that knowing your opponents name adds it to the strategical aspect, but it’s actually the other way around.
The whole point of this game is not knowing what your opponent’s doing (because of Fog of War), SCOUTING what’s going on in his base and his army, THINKING about what you’ve seen, MAKING CONCLUSIONS about his plan and then COUNTERING it — this is what you call strategy.
Sitting on your ass and not moving out ever until the last push, on the other hand, is just some blind “I’ll do something I want and hope I can win with this” — and this has nothing to do with strategy.