Refresh my memory but when did exciting, intense stealth based action games start being marketed to the Guitar Hero crowd? I enjoy my casual titles as much as the next person, but it sets a very dangerous precedent when major developers and publishers begin changing proven, unique, and popular gameplay mechanics to try and take a "hardcore" property to a more "casual", mainstream crowd.
I may not be a marketing genius, but if you have created an installed fan base of over a million worldwide shouldn't you not try and alienate them by undergoing what will most likely be interpreted as a dumbing down of a beloved franchise? Also when did releasing a "hardcore" game get to be a bad thing? Call of Duty: Modern Warfare 2 is about as hardcore as it gets and it seems to have done just fine. It does not bode well for the "hardcore" crowd when major publishers are afraid to make games marketed towards them. I live in fear of seeing a press release about "Half Life 3: Plants vs. Headcrab Zombies."