En passant has its own solid logic. If one wants to abolish it, they must also forbid pawns from moving up two squares: the two are connected. To abolish just one of them is a one-sided affair that disrupts the balance.
Conversely, if the pawns could only move one square no matter where they are, then the en passant rule would become obsolete.
Now, to abolish both rules--in order to be fair--would take a lot of possibilities from the game of chess.
As for castling, it's rather obvious: with a king stuck in the center, it would be a lot easier and the games would end more quickly.
Is this what we want? Easier and easier, not just in chess, but in every field of life? And the easier it gets, the lazier we become.




en passant is a very important rule.
The pawn that heroically marched in the heart of the enemy's position must be rewarded positionally.