I think that's a problem with an inter-networked world in general. Time and attention is finite, and there are now many sites, apps, and people competing for that attention. What you describe is every as relevant for aspiring YouTubers, bloggers, etc.

I agree that Twitter is included in that overarching problem, but I don't see it as their creation, and I'm not sure what they can do about it. (Facebook is in an easier position, being oriented primarily around family and friends, even though every brand on Earth also has a Facebook page.)