Other TOCs▸ should follow SWT▸ 's excellent example and just do away with seat reservations completely. Think of the money the TOCs would save. Get on a train, find a seat and sit in it! Having to watch people faff about all the time looking for their reserved seat when there is a carriage of unreserved seats they could sit in. You just want to say 'just sit down will you!'
I disagree with that simply because of the reason of commuters versus leisure travellers. Commuters will charge onto a train for a seat (probably a table seat) travelling as far as Reading/Swindon etc. leaving those with luggage, kids etc. to struggle on finding few seats dspite having tickets booked for weeks and travelling further afield having to stand for a large chunk, if not for the whole journey. This would ultimately lead to many people deciding not to use the railway.
I will agree though that local services could probably do without reservations but the problem is defining a local service as would people class Cardiff to Portsmouth as a local service or not?