It was needed for Safari Zone though. Step counter is a near-impossible hurdle for the hivemind, and repeated tries will drain money, which is finite in the game without Pay Day. The ROM being used is allegedly hacked to have all 151 available, except suspicions are high that that's not true... in which case, there are no Meowth to be caught. There is a TM for it, but that could easily be tossed or overwritten.
So yeah, I think Demo mode was good for this ONE part. Nowhere else though.