Why do many 1st gen tram networks stick to unidirectional operation? It seems like it's almost only drawbacks to it
>need turning loops
>can't have switchbacks for when a line is cut to run partial services
>can only have side platforms not island platforms
Last one wouldn't be an issue if the trams still have doors on both sides, but that gets rid of one of the few advantages
>more seats because doors only on one side
>a wee bit more space at the back because no second driver's cabin (although they still need auxiliary controls in rear)

Also, it's perfectly simple to gradually change over to bidirectional operation, just buy new trams bidirectional, the loops aren't a bother. You can even keep the loops in place for easier turning.

So what's even the point of unidirectional operation? Why was it even introduced in the first place, when in the early days trams were all bidirectional?