Farmers shouldn't be blocking byways...
...and when they do, they shouldn't be surprised if people (legally) take the easiest route round the obstruction, or demolish it. The Rights of Way are just that, Rights. It is sheer hypocrisy for police, councils, ramblers and landowners to complain about irresponsible offroading while condoning the obstruction of any of the very limited number of rights of way open to trail riders.
When I think of RoW like Strata Florida, you could drive a chieftan tank along that and not cause any damage, and the same is true of many other byways. I suspect it's the same old problem of eejits with unsilenced bikes disturbing the peace, and then wheelying up and down over the fragile remains of an iron age hill fort or two. But last I heard, the Monks trod TRO was being lifted for motorcycles in the mid summer months because it was dry enough to be ridden.
In addition, Southern Welsh highways authorities seem to regard the information that a farmer has blocked a byway as good grounds for a TRO, rather than for bollocking the farmer and repairing the Byway...