As with any private company they have a responsibility to their shareholders to maximise profit. It's easy to direct all our hatred towards them, because they're the entity we all deal with.
In reality however, only ICASA is to blame.
I also believe that it's not so much that ICASA don't WANT to change things. It's just that they're too much about the meetings and too little about the actually getting things done.
Meetings: The practical alternative to work.
Edit: With all that said though, I find it hard to believe that all Telkom's shareholders are content with seeing their investment go to pot in the long term, what with the crap service and potential competition looming (unless they're counting on the fact that ICASA is toothless and expect Telkom's profits to continue growing regardless of what else might happen to the marketplace).