A few observations I would like to make...
It's been suggested that it is insulting and patronising to suggest that landowners do not know their own mind. When it comes to caving related matters landowners are usually receptive to the advice and views of the caving community. Let us imagine that the opening of Drws Cefn had been greeted with unanimous approval by local cavers, clubs and representative bodies, that the landowner had been advised that this was a wonderful development for exploratory caving, for sport caving, and a God send for potential rescue... Would we now be faced with the prospect of a cave entrance being filled with concrete?
Moving on to the OFD Top Entrance question.... Yes, there are a few cavers who wish history could be re-written and that OFD 2 could be the preserve for a minority of elite cavers undertaking 10+ hour trips. I think these people are utterly selfish. What about the 1000s of cavers who have enjoyed this wonderful cave over the last nearly 50 years? What about the pleasure generations of cavers have derived from enjoying the fantastic through trips from Top to Cwm Dwr or One?
OFD and Draenen are both, by their nature, multi entrance caves. The 'wilderness experience' of the few is achieved by denying this reality and depriving the majority of potential trips and experiences that would be of the highest quality. Ogof Draenen could experience a renaissance of exploration, and quite possibly achieve the status of longest cave in the UK.
So here is the situation - Drws Cefn has been open for several years and is, presumably, occasionally visited. What's the problem? Why take these extreme measures to resolve a problem that isn't? I wonder if this is why.... It must be a strange situation for the small group who are still active in the cave. They have to cave for two hours on the way in, knowing they don't need to, and then the same again on the way out, always aware that they could shave two hours off the trip. But they can't actually use the entrance can they? Not after their crusade against it. But it's there... always there at the back of the mind, when staggering, already exhausted, down Elliptic Passage, that there's an exit 10 minutes away.... Solution - fill it, concrete it, unmake it.
If the landowner wants it closed, then let him do it, and if he's not sufficiently motivated to bother, then let the cave stay open. That being the case it would be time for others to swallow their pride, use the new entrance, and quite possibly embark on a new wave of exploration that will extent their beloved 'wilderness' into new frontiers.