Daniil, you are right that it would be more interesting and more complicated if all pieces were both walkers and jumpers. Someone suggested this for my hyperchess game also, where it is equally true. The problem is in the complicated part. The game becomes too complicated to play with any ability at all. Of course, a lot of people like that sort of game. Here is where I prove I actually am conservative in some things, because I am not one of those people. 

This game is something of an examination of how small a dimension can be and still be 'useful' in a chess sense. It pushed me into looking more at 3D and 4D games with an eye toward playability. Chess on 2 Boards [a bust], Taxi, Directed Alice III, and 3D Great Shatranj round out my foray into higher-dimensional chess.

I am not the only one who thinks it's complicated. Daniil, you are the second person in the world to play Walkers and Jumpers with me, the first being Abdul-Rahman Sibahi, who made the preset. I have played a few games of Hyperchess against different opponents, but don't get a lot of second game offers. Directed Alice and Chess on 2 Boards have never been played all the way through. Taxi and 3D Great Shatranj have never been played. People are not eager to play highly complex games they think they won't understand.

To be honest, neither am I. I do not want to play Raumschach or Chesseract, because I think they are too complicated for reasonable play. You don't find many people who will play a game if they know they will look like complete idiots trying to play it. [As recent TV programs have demonstrated, however, you can find some...] It doesn't make any difference how easy you make the game, if people think it's too difficult for them to enjoy it, they are unlikely to play. 

On the other hand, since nobody plays these games, why not add versions that are more complicated? The extremely few people who might be interested in the original game would more likely than not enjoy optional versions.