But, with a lower barrier of entry, you can bet that there will be many more push channels from which to choose. Not much different than the way the Web is today. Creating and maintaining these profiles can exert a huge burden on users, assuming their information needs can be expressed in those profiles. And those kinds of needs are often are satisfied by infopellets. I doubt that users of push services will be bothered to maintain such profiles, even if they were sophisticated to handle such complexity.
Profiles are also bad at anticipating users' future information needs.
We program them to know what we want or don't want from a limited palette of selections that the push service makes available. And like any good piece of software, these profiles do exactly what they're told. And we don't and can't tell them what will happen in the future, much less which events will be of interest to us. There are a lot of other negatives regarding push technologies that have already been described more eloquently elsewhere, so I'll stop there. The drawbacks that I have mentioned are essentially problems of information retrieval.