Well the thing is, old games are often something quite different to the new games. I.e. modern games are not trying to compete with the old games... and old game was great for X Y & z reasons, the developer thinks, ok, well we dont care about X Y or Z anymore, they are outdated paradigms... lets make a version that fits with the modern paradigms.Simeon Ivanov said:Are older video games better than the current, or is it just nostalgia and fanboyism that blinds us?
So the question really comes down to weather old paradigms are better then the new paradigms, and the answer to that is firmly based on what you're looking for in a game.
Lets take one of your examples, Call of duty vs modern warfare. When you actually look at the differences these are in fact very different games. Modern warfare (series) has very short fictional single player campaigns, and CoD has long historically based SP campaigns. Multiplayer in CoD is more or less an after thought add-on, multiplayer in MW is pretty much the entire point of the game. These are just the most stark and obvious differences but its easy to see how some people who loved the CoD games can hate the MW games without age even being a factor.
I think this extends to more than just CoD too, pretty much any long running series will have design changes over the years that some will like and others wont; and on the whole those design changes will be focused on selling the game to the changing wider demographic. Gamers aren't just nerds with 11" monochrome crt monitors anymore, they're everyone and their mom.