It's not quite that bad, (though it is bloody annoying)
The inclusions are (probably) natural cup marks, the white stuff being chalk used by the boulderers.

It's a long running bone of contention. The boulders are scheduled monuments, but are also contain well recognised routes for the boulderers, and were used for climbing well before the carvings were recognised. Some of the routes are on bits of the boulders without carvings, others are right over them. It's the latter routes that have been publicised amongst the climbing fraternity (most of whom seem quite happy to avoid the carvings) with an aim to raising awareness of and consequently protecting the carvings.

It's not illegal to climb on a scheduled monument, but it is illegal to damage one. I reckon climbing won't be banned unless the carvings are damaged at some point, but by then it'll be too late :(