More the state of the UK, most of Europe it is still like this if you avoid commercial / industrial towns (Not normally on my itinerary)What a state the world is now in.
In our bike travelling days back in the 70’s and 80’s in the UK and northern Europe we would just park anywhere, use the ‘quality’ Triumph steering lock and clutter off. Mostly the bike would have all our holiday gear on it as well.
In the Alps you see most the locals just park up, hang their £500 lid on the bars, thrown their £1,000 textile suits over the seat and wander off.
As well as shit-holes, I forgot to mention Motorway Services are probably a bit iffy as they attract thieving scum, never had a problem, but we tend to stay close to the bikes or lock everything away (I keep TB fairly empty so can thrown lid and sat-nav in there if we plan to sit inside services for food / drink, or if it is nice we eat / drink outside where we can see the bikes.
Touring the UK is something we don't do much, if we do then I make sure it is a nice area and there is at the very least a long drive way to a private car park where the bikes will not be in view of the road, and will be close to the reception area or our rooms. If in a town or city I would insist on a secure private car park and still chain the bike up.