Despite your feelings on the Halo franchise, it is pretty cool that even a game that is six years old is (well was) still supported by a committed fan base. Think about how many great games have come and gone out of our memories and minds in the last six years. Not a lot of games really have the staying power to continue to be popular for that amount of time.
It also begs the question why Microsoft, along with other publishers and developers, don't allow or give the ability for fans to host their own private servers for their favorite console games. Would it be such a security risk to allow private server support for consoles? Fans have been doing it on the PC since the dawn of online gaming with no ill effects. How much goodwill would a company like Ubisoft or Activision (who could really use some good press) receive if they just allowed their fans to run dedicated servers? How much goodwill would Microsoft get if they just allowed their fans to run dedicated servers for old XBox games? It would be a virtual zero cost move that would go over well (in my not so humble opinion, of course).