Correct (as far as I know) that one needs a licence for any television or radio receiving equipment, regardless of for what they are used to receive (?????).
The point that some who receive benefits such as free licences, winter fuel allowance, bus passes etc could afford (and would be willing to pay) for them is a good one, however it would seem that the cost of means testing would negate any savings made.
My mother used to give her winter fuel allowance to charity, and I know of a couple who practically rub their hands when they get theirs, as it goes towards one of their many holidays!
The same couple also religiously claim their bus passes, despite NEVER travelling by bus, because they have a mobility car, pay no road tax, but will take up staff time and resources to get them because "we are entitled to it, therefore we will have it".