Well, Stealth Rock isn't really, it's actually really useful and helps hurt certain Pokemon which can otherwise be big issues otherwise. For OU, Volc/Dragonite, and for NU, Charizard, etc. So it's definitely a useful TM since even with it these Pokemon are still issues in competitive play. However if the TM was added, then those Pokemon would be less of an issue since there would be more SR users and less need to dedicate an entire spot to it. :x Sooo yeah, it's definitely useful and could be beneficial if returned.
I always thought that they took out the TMs that they did to balance the Metagame more. They took out the really threatening attacks that would be heavily abused with the Reusable TM thing. Gamefreak supports Metagame so I know they are making more competitive changes to promote Player vs Player battles.
I see bringing back Stealth Rock as a serious issue due to abusibility. It was removed for a reason what ever that may be, and seeing as Gamefreak is pro meta I think that had something to do with it.