You know why there's no "originality" nor "variety?" It's because it's in the eye of the beholder. Just because you think something isn't original, doesn't mean that someone else doesn't either. Also, the majority of people gravitate towards the same things. The community shows you what they like and what they're into, and creator's create to satisfy that need, as it were.
Many people love Street Fighter. They probably grew up with it. Let's take on person from that group. Maybe that person see's two different Ryu's completely differently. They see the first as source accurate and the second as custom. Well, by definition, the custom Ryu is adding variety to the mix, because the author decided to do something different.
You can't simply assume that your opinion of mugen is the same as everyone else's. I swear, it's like the same exact crap from MFG...