Because, given time, you can infinitely increase any stats but luck, disp and possibly joy. The new two stats are strictly monitored (by me
![Smiley :)](https://www.pinkpetal.org/Smileys/DarkB/smiley.gif)
) to not allow high values.
Specific traits and rare, powerful items also increase and decrease them, making a big difference between characters in battle. If tied to the same old stats, the said difference will be lost very soon.