The only problem is that the moment that they change any of their flagship tittles drastically everyone would complain "OH NOES THEY ARE ABANDONING THEIR ROOTS!" "NINTENDO HATES ITS OLD FANS" etc...
remember when Halo wars came out, and like 50% of halo fans hated it, now imagine if it was halo 4? that would kill the series stone cold.
Let me also point out that based on your argument, you must be really getting tired of Guitar Hero, you've essentially played the same game how many times now?









