I can see both sides the argument.

I also predicted there would be reporting to the relevant authorities, whether it would be out of malice or not.

The reference made to freight transport is interesting.
Rules are made and are made to be adhered to.
Whether this is taco's, CPC's or ADR plates.

Just like the rules which have been made for passenger transport.

If a freight transport operator breaks a rule on the carriage of dangerous goods and doesnt display a UN number, they can be punished.

Just like a passenger transport operator can be for not displaying the appropriate detail on their vehicle.
As has been said, the rules haven't just been dropped in from a great height.

However, I do agree with the comments made about vehicles which are low floor and how they're suddenly unsuitable because of a few millimetres.
I wonder if this is a politically motivated initiative, rather than one based on recommendations.
As has been said, the cost to replace or alter a vehicle can be huge.

Legislation in housing has changed over the years. Downstairs toilets need to have a certain width and doors need to be positioned in a fashion that doesn't break rules if built beyond a certain date.
However you don't see perfectly good homes destroyed or adapted to suit this legislation.