Just shows how short sighted people are because they think it will "teach em good".
The people this is supposed to be targeting (bikers with small rear plates) will still be just as unidentifiable and untraceable as they currently are.
However now people who may have been pulled for an oversight (a dirty plate for example in the middle of winter) and may have been given a stern warning or maybe 100 notes fine if they got a copper in a bad mood could be looking at upto £1000 fine and 3 points.
Points should be used when someone is a risk to other drivers, not as a punishment for minor transgressions.
And you then refuse the FPN and argue in court with a trio of magistrates who will tend to take the sensible side of things.
No one is realistically going to get done for a dirty number plate unless the rest of the car is spotless...I've actually seen a first hand account from a police officer who pulled one idiot for speeding and gave him a wet cloth to clean the filthy plate at the side of the road before he allowed him to continue, the rest of the car apparently looked like it had just been washed, the number plate however was oddly covered in mud like someone had applied it on purpose or very deliberately taken steps to avoid cleaning it.
As he put it (from memory) it was obvious that the guy had tried to obscure the plate to avoid ANPR but it was far easier to give him a rag they kept in the car than to do anything else especially as the guy had been a real idiot.
The law already calls for your vehicle registration to be displayed clearly, now whilst they don't explicitly say "keep it clean enough to read" the intent is there but you have a very good excuse for not having it spotless*, unlike if you've actively gone out to get a plate that flatly breaches the legal requirements.
There are unfortunately a subset of people who will see any motoring penalty that is purely financial as nothing more than the cost of having their way, it's the reason we ended up with points for using your phone as people didn't consider a £70 fine when they got caught a penalty worth worrying about.
*I can't remember the last time I saw a number plate that was too dirty to read (commercial drivers who work in/around mud tend to clean them off, even if the rest of the vehicle is filthy), plates that are obviously made to try and confuse ANPR/people on the other hand I see virtually every time I go out.