It is all about the history presented in there. They are with them for all sequels, no matter if they are more or less successful. Those most hardcore players accompany them from the first moment, as soon as computers were used as a source of entertainment. It perfectly shows how many magic can they hide. Those types of series are basically for quite a long time on the market, some of them exist dozens of years.

You can find at least hew multiplayer games of pc that can be called legendary in the widely understood computer gaming entertainment.