Besides being businessmen... They're ultimately artists. A lot of artists want to evolve and expand in whatever their forum is. It's like a band that releases a killer debut album and then decides to evolve their sound with the next album and it ends up killing as well. But some people are always going to want that band to keep re-releasing that debut album over and over. That doesn't satisfy a lot of artists.
I see a lot of that from people when it comes to MKX. They want the debut album again, not a new one. I think some of you guys that didn't like 3d MK and only want characters from UMK3 and before are high. It must be pure nostalgia at play. To say nearly all characters from MK4 on were "bland" or "unoriginal" seems baseless.
At WORST, characters like Havik, Kenshi, Hotaru, Quan Chi, Reiko, Drahmin, Shujinko, etc... are no less dynamic in design as old school characters like Jax, Nightwolf, Johnny Cage, Liu Kang, Sonya, Kung Lao, etc. (which are all characters I like as well)
Personally, I think a lot of the post-UMK3 characters are some of the most bad-ass character designs in the entire series. I'm fully supporting the large number of new characters coming in MKX. I expect some fucking sick designs.