Having the ability to do something doesn't mean it'll be focused that way or convenient to use that way.
Look at Twitter and say: "why won't blogging kill this?" Part of the answer is focus: they're making some things easy, not just possible.
Part of the answer is demographic/cultural. Reddit isn't Hacker News, even if a lot of the technology is very similar, and StackOverflow isn't any of its many different-topic clones even if nearly all of the technology is shared. A community is affected by focus, policies and advertising, not just the technology.
If Google Wave has the technology to kill most web startups (I'm not sure I believe this), then it's not focused enough to matter in almost any of their specific domains.
As one of the co-founders of Ramamia, I have to say this is a great answer, probably even better than I could give. Domain and niche expertise is powerful.
Look at Twitter and say: "why won't blogging kill this?" Part of the answer is focus: they're making some things easy, not just possible.
Part of the answer is demographic/cultural. Reddit isn't Hacker News, even if a lot of the technology is very similar, and StackOverflow isn't any of its many different-topic clones even if nearly all of the technology is shared. A community is affected by focus, policies and advertising, not just the technology.
If Google Wave has the technology to kill most web startups (I'm not sure I believe this), then it's not focused enough to matter in almost any of their specific domains.