Are rational the carriers concerns about PoC (push to talk) ? (I)

We found that typical succesful services in growing markets as push-to-talk are not being launched publicly in mature markets as European Union markets are.
Carriers are focused about avoiding loss of revenues from services they think could be partially cannibalized (voice and mostly SMS). Are they right?
In my opinion they are not right, and the impact is the net loss of possible revenues and the misuse of the data network capacity. We should not conceive the push-to-talk as a mandatory mobile to mobile communication (then of course, perhaps it could happen a partial cannibalization for little communication of short voice calls and sms).
There are real services as push-to-email (by Pacific Datavision) mobile-to-server-to-email account, and it is not possible with SMS with same length.

The executive culture unfortunately is priorizing the "avoding risks" and not the "catch the opportunities" and possible mobile use cases with current handsets and networks are being delayed and delayed and interesting ARPU increases are being left by carriers.

a pity then :-(

juan mateu