Many public toilets are modernising their facilities. Replacing their old roller towels with new high powered hand dryers. Good news for normal folk, not so good for the fatties!
Due to their enormous bulk, they are unable to reach certain extremities. Hygiene is already an issue for them due to their excessive sweating (usually in the presence of salad or at he suggestion of physical activity). The inability to wipe will only add to the problem. At least with roller towels they can floss the parts they can't reach.