I agree in so far as in the air, a pilot only needs to receive RT from ATC and also from other aircraft, for receipt of instructions, advice and for the aforementioned situational awareness. However, it is a fact that on the ground, vehicles are likely to be on the manouvering area and should be regarded as "traffic" (sorry, can't think of a more suitable categorisation here). I guess many pilots would like to see AND hear what these vehicles are doing rather than solely relying on ATC for this information.
IIRC, when the current voice switch was installed at LBA in 2005, there was a complete cross-coupling facility for the first time at the airport. I think it's only in recent months that the facility has been reduced to its current "two thirds" status. It may be down to an equipment failure but I doubt it after all this time and I can't see the facility being withdrawn for cost reasons. Perhaps it was a pilot-driven decision.
By the way, I say all this from the point of view of a tug driver with a local RT licence. My transmissions have been stepped on more than once ! As for RT discipline, it is on the whole of a good standard at LBA. There is at least one semi-retired ATCO involved in the training and the ASU make you work for your annual validation, as would be expected.