I like the idea of being able to make our own nether portals. After a certain amount of time all the resources around Nether spawn are gone.(Netherwarts, claimable land, Glowstone) Having to travel further in the nether is a lot harder and longer then it is in the overworld. Having your own nether portal is your own risk too because other people CAN come from the nether into your portal room.
Also people can camp the nether spawn easier because its protection zone is smaller. example nether is like 15x15 zone(with only 2 exits) overworld has 4 exits and is a LOT bigger in area size such as 100x100. Not to scale.