Migrating to open standards is the right thing for Adobe to do, but that's not how Adobe likes to do business.
Adobe is lazy. If there's a problem with their software, they'll blame it on somebody else, because talk is cheap. If that doesn't work, they'll wait until the last possible moment to actually put in the time and effort to improve their code. It's a pattern that is most evident with their Mac software:
CS5 (released April 2010) was the first version of the suite that was fully Mac OS X native. (Mac OS X was released March 2001). Prior to CS5, they were still using the Mac OS 9 GUI APIs, which, though they weren't officially totally deprecated until June 2007, were obviously always just a transitional compatibility environment. Even prior to the official deprecation of the Carbon UI APIs, Adobe had plenty of reasons to port to Cocoa. Number one was to provide a truly OS X native look-and-feel, which is pretty much impossible to emulate via Carbon.
Adobe's approach to dealing with Flash performance on OS X has been similar. When people complained that video playback was unreasonably slow (ie eating up 5x the CPU time that a standalone player would use), they blamed Apple for not providing them with direct low-level access to the video decoding hardware. When Apple called their bluff and gave them exactly what they asked for, Adobe released a flash player that used those APIs but wasn't noticeably faster for anybody, and introduced several new glitches that made it a step backwards for everybody who's Mac predates the NVidia 9400M chipset.
On the Windows side of things, Adobe's PDF reader has been such a long-standing resource hog that third-party PDF readers have garnered significant market share in spite of their lack of support for most of the recent advanced features of PDF. If Adobe would take better care of their PDF implementation, it would be good for the progress of the format overall.
Further back, Adobe kept their font format (PostScript Type 1) proprietary and expensive so long that Apple had to create TrueType, and Apple ended up licensing it to Microsoft. Several years later, Adobe abandoned Type 1 in favor of co-developing a TrueType-based successor (OpenType) that is finally re-unifying the font market.
Adobe seems to think they're playing it safe by being the last rat off each sinking ship, but one of these days, they'll be too slow.