The game was also made 10 years ago and is still evolving. You can't change an entire core function overnight.
well, obviously. but seeing the direction the story telling was taking, I highly doubt they will make it more interactive. they did add more voice overs to some of the later content, but again - variable, player determined conversations are not Blizzard's style. its more of a bioware/bethesda/obsidian/project red/etc style. I can recall very few quests where player determines what happens to a degree and then it still goes absolutely nowhere, its just little flavor bit. which is fine for the style of rpg that blizzard tends to create.
but what does amuse me is that often times - people demand that some of the core functions in SWTOR are changed overnight... becasue apparently its a reasonable request for this game? >_>
one thing I'm kinda feeling bemused by is that Blizzard will literally be offering sanctioned powerleveling once warlords of draenor hit. what with one free boost to lvl 90 and with more boosts for more characters being purchasable. another sign that they are probably not planing on changing up story telling methods all that much, definitely not retroactively... seeing as they are more then fine with people skipping all but newest content.