Probably the main reason why TV Offal is not repeated is because it was mostly pants -- far more miss than hit. Aside from the occasional funny skit (e.g. overdubbing BBC archive violin solos) there were dozens of increasingly tiresome camp dalek episodes.
It's the same reason why Jam or Q9 or early Kenny Everett is never re-shown.
I remember a few years ago Graeme Garden bemoaning the fact that the Goodies was never repeated. When some station finally broadcast a few, it was perfectly obvious why they'd been left to decay.
To be honest, I think it's a big misconception that certain shows are held back purely due to being "dated". In fact I think the one question involved when putting something out on DVD these days is "Will it sell?" I'm pretty sure the only reason the entirety of Milligan's Q(or however much of it is still in the archives) hasn't come out before now is that whoever holds the rights doesn't think they can make enough money out of it.
There are many still many shows that are never repeated ir put on a shiny disc but which has sod all to with them being "dated". To name a few, Innes Book Of Records, Rutland Weekend Television, all of Sykes apart from the first series, etc.
Jesus, they even put out "The Wheeltappers and Shunters Social Club" on DVD, and show me a format that has dated any worse than that.
Jam still holds up as far the material is concerned, even if much of it was watered down from the radio incarnation. As to why it's never repeated, who knows? It could be to do with the peculiar format(20-odd minute episodes with no ad break in the middle) or possibly some of the material is still too close to the bone even for the supposedly edgy and in-your-face Channel 4. Or maybe it's because the schedulers have zero imagination and would rather just put on 8 Out Of 10 Cats or Father Ted on for the billionth time.
As for The Goodies, those shows might not be as hilarious as their reputation suggests, but after watching the repeats last christmas, I started to realise they have a strange atmosphere and rhythm to them which kind of grows on you after a while, much like some of the weirder Python episodes. Just as long as you don't expect belly laughs.
I suspect the only reason Smashie & Nicey: EOAE has never been on DVD is that 2Entertain are too stingy to pay for rights to the numerous songs and clips featured. It was on TV in the last couple of years, and actually seems funnier than it did at the time - it might be one of the best things Enfield and Whitehouse have ever done in my opinion.
