Perhaps. However the fact that people might not live somewhere doesn’t invalidate their observations. Those from outside who work or visit London are indeed likely to be less acclimatised to the state that elements of the city are now in.
When you work in a city where you have to be careful about exhibiting your watch or having a conversation in your mobile in the street, it’s entirely reasonable to conclude that something’s gone awry, especially when it’s something that’s arisen or got worse.
As for political points, it’s entirely reasonable and legitimate to question how the politicians have allowed such a situation to develop. From the state of the Bakerloo line, to the violent crime stats. I’m not going to single out any particular politician, IMV they’re all as bad as each other, going back some years, and involving all the parties.
It isn’t that hard to provide a Bakerloo fleet that isn’t covered in scrawl. Clearly presenting the Bakerloo Line properly just isn’t a priority to the powers that be, either in terms of cleaning, security or law enforcement.