I'm with Cusco and IO540 on this one.
The overhead join is for the twirly tash brigade flying slow non-radio aircraft using their monocled mark one eyeballs.
I'll take the second punch then! Apart from the twirly tash bit, I kinda fit that group. However, I think the OHJ is daft and is the time I feel most exposed to a midair. I hate arriving overhead to hear two or three others doing the same (where are they?) I tend to ask for a downwind, crosswind or straight in approach and usually get it .... much safer. OK, I have a radio (handheld but good range) and accept that without any contact the OHJ has merit. But few fly these days without any radio, and those that do, tend to fly non radio into private strips or airfields where non radio is common. G-VFWE works well because by and large, the pilots are very experienced and have good situational awareness, so the odd non radio a/c can easily fit themselves in.
SS