I don't. i just hate the further discussion of a game that came out over a year ago. I've defended it enough. I like it, some dont for one or more of several reasons.
a) Genuine dislike or not clicking with it. Prefer different kinds of shooters, or anything but a shooter
b) See it as representing Microsofts over eagerness to make money
c) Are old school playstation owners who dislike it perhaps because it saved playstations new rival from eating dirt.
d) Were expecting more from a sequel to one of the most influential, groundbreaking and potentially best FPS's of the early part of the decade
e) Many were dissappointed with Halo 2, so Halo 3 isn't going to really change their minds, seeing as Halo 3 is more Halo 2 than Halo 1.
f) People don't feel it deserves all the attention it gets (which should be a lot less seeing as it has now been over a year) and get a bad taste in their mouth when they think of people placing it as number 1 gmae of all time in their living memory
g) People mistakingly think the multiplayer consists of 1.5 million 12 year olds, and them.
People like it because:
a) Mulitplayer is very good, so long as Halo floats your boat
b) They like the first halo, so why fix whats not broken? If you want something new and revolutionary (which admitedly, in my honest opinion, there hasn't been anything huge and infinitly better in some way since Halo 1) play something else.
c) The story may be no Fahrenheit/ Indigo Prophecy, but it holds together and I for one was satisfied enough.
d) They have come to terms with the fact that it is merely in the top ten Xbox games in most people's lists, rather than being a favourite, and even if some people do like it over Half Life 2, then that is their choice and they should respect it.
I like Halo 3. It's in my top ten, but I suppose the biggest reason people dislike it now is
h) People won't shut up about it on forums.