Loo rolls are the last use in the paper re-cycling chain, and presumably, Izal was a heavier paper than tissue, hence the current best-use.
I can remember at school, having those blocks of folded paper nailed to the wall, and all the sheets fluttering to the floor after a few seconds in the dark, trying to find the loose end...
Mind you, Kleenex and others try to hide all the opening edges, so you finish up with a fistful, so they learned fast...