Necessary for fighting and keeping up the challenge presented in DMC 1. DMC 1 had survival horror- esque elements, having a limited moveset was a part of that and was meant to put up the challenge of having to be stylish while only having those moves to use while your enemies are able to adjust to repetitive attacks. Having a deeper moveset displaces the difficulty of that challenge towards how well you can combine a series of moves instead of how well you can utilize only the few moves given to you.
The idea of stylish combat comes from the challenges presented in survival horror games. In survival horror games, you have two challenges:
- To stay alive
- Utilize your resources effectively.
Stylish gameplay presents the same two challenges in a more difficult degree:
- Receive as little damage as possible.
- Combine your moves in a smooth series of actions and well- timed evasions.
So in order to maximize the challenge, the number of moves should remain as minimal as the game's difficulty should allow. From the POV of a developer, this can be done by thinking of DMC as a survival horror game and work from there. As a player, the best thing to do would be to limit the amount of moves you can use and play using those.