The Design Philosophy That Led to Vanilla's Success

I know most changes that lead to "new age" WoW were praised, although they were wrong changes from this different design philosophy standpoint.

There is no such thing as objective "move forward", and certainly no "requirement" to do so. Instead it's mostly just badly understood principles (without knowledge of all their consequences) that are implemented through mass suggestions and the perceived certainty of progress. John Gray has commented on that: https://youtu.be/jmRBHCclzZk

Without going too much into politics (because the rules of this subreddit prevent me from refuting your claim, i.e. this discussion takes place in an inherently skewed environment), I'll just say that I agree that the 2004 devs didn't expect millions to come, but layering is not a solution to login problems, it's just their modern server structure that they have to use to minimize servers idle resources.

/r/classicwow Thread Parent