I think it’s disingenuous to use line names such as “Metropolitan”, “District”, “Central” or “Waterloo/Hammersmith & City” lines as examples of poor naming.
The vast majority of those lines were built prior to the formation of London Transport in 1933.
In fact if we go by the Metropolitan line, which was the Metropolitan Railway it did in fact live up to its name at one point, since it served the metropolis of London, and I don’t mean its current incarnation of Aldgate/Baker Street to Uxbridge/Watford/Amersham/Chesham, until 1990 the Metropolitan line served most parts of London, the Hammersmith & City and East London lines were once branches of the Met that took the line into South East London, East London and West London, plus if we include the District line (formerly Metropolitan & District) then it also served South West London too ergo it was a line that served the metropolis
The Central line is probably the most central of the lines and serves both the City and West End of London.
The Hammersmith & City and Waterloo & City lines does what it says on the proverbial tin, links those areas with the City of London.
The Northern line in hindsight is probably the best name for it despite it going further south, seeing as the southern end goes deep into Southern Railway territory (at the time all railways south of the river were known as Southern Electrics) so a Southern line and Southern Electric at Balham would have caused some confusion especially as Balham is on the Southern Railway network.
By the time LTPB was formed in 1933 the names were ingrained and most knew their function and what part of the city each line served, so they stuck.
The new names for the Overground reflect nothing of the areas they serve, except for perhaps Mildmay and even that’s for the wrong line, these are vanity projects to feed an ego and are self congratulatory as being “look at how diverse and kind we are”
The fact that most across the political spectrum have reviewed this as being poor shows that it’s not just the so called “gammon” or anti-woke types that think the names are utterly stupid.
If the Overground takes over other rail lines in London; ie the Dartford/Gravesend routes or the Great Northern inners, what names will they be given? They’ve set up a precedent now.