Talking about horseshit you put Valve, Blizzard and IW together? Hahaha.
Halo's influence on the industry is the destruction of the FPS genre. The attempt to create a competitive community in halo is such a joke I can't even tell. It made people think the game was balanced, interesting to play and fast paced which it is not. It appealed to the hipster community that's all. What you list as achievements in game developping are either irrelevant (AI really?) or laughably wrong (weapon sandbox...). I don't consider match making as awesome or innovative. It's just a way to simplify matches setup for console gamers. How does this make the genre improve? It doesn't. Finally the stat tracking you talk about is probably the biggest joke of all. So Bungie introduced a Facebook type application in their game, how cool! You don't even know how many stats could be collected from PC games more than 10 years ago.
True big FPS were released around 2000 and were infinitely superior to any kind of Halo.
It's not strange. Thanks to Halo the competitve FPS genre is dead. Thank you Bungie? It's not a matter of touching the game or playing it regularly it's just a matter of genre regression and over simplification to the point that it's not even interesting at all anymore. I'm quite torn between blaming Bungie or people who bought the game for killing my favorite genre. But I can only blame Bungie because if they didn't ally with Microsoft and organized a giant brain washing ad campaign for the launch of xbox maybe the FPS genre would still be in full shape?
Also, everybody knows that there are some improvements in the halo sequels (and some horrible design choices too) but the argument that Bungie sold the same game 5 times is valid because the changes are so minimal it can't justify more than a patch release except for a new campaign. I don't see more difference between the Halo's and HL/Op4.