I agree to a point. I'm not bothered myself, but the owner of that car might be paranoid about some scrote sticking their plate on another car and racking up speeding fines and congestion charges on their behalf (especially as we now know what colour the Puma to which that plate belongs is, and that we need to avoid Coventry in our clone - Ian G had a Red Puma up for 500 notes the other day - not a lot of money for a scamster to have carte blanche on the roads at someone else's expense).
Or there's the view that at this stage there's no indication they're a fine upstanding member of our online community - they may well have been up to no good at the "Wheatsheaf Theatre" that day - perhaps they told their Mrs they were working late, so they could attend an evening performance of "Top Gun" in order to satisfy their latent homosexual tendencies - we just don't know!!
I think that no good can come from posting other people's plates without their knowledge and/or permission.
PS - apologies in advance to the owner of above car if they stumble across this thread!