Why is '-- type radio' needed?

[J]

David Cantrell wrote:
> When I download stuff why do I have to tell GiP that I want a radio
> programme?
>
<snip>

Users not in the UK and possibly on a slower connection than the UK 
norms may well seek to download only those non-TV programmes properly 
made available to them so may have GiP initially launched with 
--type=radio in the command to avoid refresh of a TV cache and 'type 
radio' specified in each pvr file.

Given that updating of the TV cache may take quite some time, is it 
actually reasonable to mandate that GiP maintains their TV cache so as 
to allow auto-resolution of the type of a search string?

J