Why no Olympus "pro" standard zoom

Does anybody here think that Olympus will make a "pro" standard zoom lens? By "pro" I'm referring to something with a fixed aperture in the 12-35mm or 12-50mm range. Panasonic makes the 12-35/2.8, but it would be nice if there were another alternative (one without the OIS). I see that Oly has a 14-35mm f/2 for Four-thirds; it would be nice if something like that was made available for Micro four thirds. Same with the 12-60mm/2.8-4 (though it's not fixed aperture, I wouldn't mind since f/4 is still pretty decent). And no, I don't want to shoot with a 4/3 to M4/3 adapter.

Been shooting with the Oly 14mm, Pany 20mm/1.7, and Oly 45mm as of late. While I do enjoy primes, I'd much prefer a sharp zoom for less critical, day to day stuff.