I never understand this obsession with pax cramming everything into the cabin and at most airports there is rarely a wait of more than 10 minutes at the carousel. This is because at least 15-20 minutes have passed by the time you have got off the plane, walked a good few hundred metres, up and down a few escalators and queued at Immigration.
Last time I checked a bag I was at the carousel in under 120 seconds of doors opening [I had done immigration at the previous airport] and then waited about 30 minutes before it was clear that my bag would not be joining me.
This was the third time that happened in the same year—every time with BA, it doesn't happen with KL/AF/AA/US/DL/AZ, but I accept that is bad luck.
If BA gave a cast iron guarantee that your bag would be waiting for you before you got to the carousel or your money back, I would consider it more often.
Or if bags could be gate checked and promptly delivered back to the gate, also fine.
But the fact is that you check a bag and it's another thing out of your control, in the hands of someone who couldn't really give a stuff if you are delayed for 60 minutes. That is not something I want to pay for. I would pay money to avoid this.