>In a perfect world, some designer would come along and incorporate carefully selected bits and pieces of the new version, probably with some novel changes to balance it out, and end up with something superior to both classic and new WoW.
this is exactly what they put a lot of effort into for 5-10 years or so. years! blizzard convinced themselves that the players asking for classic didn't really want classic, they just wanted some of the feeling of classic bolted on to the current game.
but players actually, really, 100% truthfully, no exaggeration, wanted classic WoW. not retail WoW with some classic-feeling bits. they wanted (basically) bug-for-bug classic.
and it worked out great in the end! classic is thriving. retail is thriving. no balancing act between the two player bases needed.