Spontaneous Explosions

Potentially contriversial Minecraft opinion:

Nether portals should slowly transform the ground around it inot netherack and magma.

I only say this since the ruined portal structures, which have been there for a very very long time, have netherrack around it. 

I don't mean that you go mining, or exploring, come back home and oh no, everything is netherrack. I mean a really really slow, and managable rate.

Could be a detail or somthing, Idk.