It seems like not a day goes by that I don't wish that same thing. But the reason I think they wont change it is because Bethesda Softworks sort of clings to the popularity of Bethesda Game Studios in order to gain a better reputation. That, of course, hurts Bethesda Game Studios on occasion. But I don't think Zenimax is aware of the negative aspects and wouldn't be able to understand why we would want it changed.
Bioware released a teaser trailer for some game that will be officially revealed at the 2010 VGAs on December 11th. There was supposed to be another reveal from another company but I'm not aware of whether or not it has been revealed yet. But yeah, some people here thought that other reveal might be TES V.
How isn't ZeniMax aware of the negative aspects? A stroll through the forums makes it clear. "Bethesda/Obsidian, you guys released an unfinished, crappy product. I'm never buying one of your games again!" and "Obsidian's product only came out rushed because Bethesda forced them to release it!" both make the mistake of taking a shot at Bethesda, the Bethesda that created Fallout 3 and TES series, not, what is in reality, ZeniMax's publishing department. I doubt their sales will be affected too much by the vocal minority screaming about robbery and impatient force by Bethesda, but Bethesda Softworks publishes too many forgetful products to be fair to the company who has had a consistent record of developing very well-received games over the past decade. The similar names have only harmed Bethesda Game Studios, as far as I've seen and well-known game series, such as Doom, don't need Bethesda's title to sell well, especially when that title is plagued by a common thought of mediocrity, and crappy games only tarnish Bethesda's reputation. What does that leave, perhaps a future balancing out at best of Bethesda's reputation instead of staying at an advanced level of superiority and no change in the receiving of money? I'm no businessman, so I'm probably wrong, but I don't see how this benefits either ZeniMax or Bethesda, who have a negative plague attached to their name while they toil away on the games they actually develop so sparsely for 3-4 years each, and still get screamed at for creating unfinished products they had no part in creating.
Two Mass Effect games and one Dragon Age game release by Bioware with another Mass Effect and another Dragon Age already being announced before we even get an announcement for one Elder Scrolls game, eh? This is what I was referring to up above, and Bethesda still gets yelled at, despite working for a longer period of time on a single project than a certain other RPG company.