My logo has PCLN, it makes clone CFLM on the corners, you delete it, I delete your face. Also, BCLN is useful for bombs, for example, you want a bomb to be blowing up longer, but you don't want evidence of clone? Use BCLN.
Why not get rid of noble gas? It can be achieved by other means. Why not get rid of the extra firework option? I can be achieved by other means. Why not get rid of heat switch? It can be achieved by other means. Why not get rid of insulator? It can be achieved by other means. Why not get rid of DESL? Its just another explosive element.
Answer to all. Because it is the way it is, and it works better that way.
Without PCLN we won't have compact electronics, different new types of creations, and, my personal favourite, PCLN is a lot better as a clone than CLNE. In conclusion,