I got a reminder for mine when it was required to be renewed.
I didn't begrudge the £20. If you can afford to run a car, you can afford the cost of the licence. If you can't afford it or think it is unfair, don't run a car.
I can't see the fuss personally, the admin costs of updating the picture needs to be paid for. It is only fair that the person who gets the benefit from the licence it pays for it, rather than coming from general taxation.
How much is a passport now? Considerably more than £20, I'd wager. Nobody suggests that they should be given out free to all and sundry.