PropDr
FRF Addict
PropDr, the circuit boards are going to be your limitation. I'm sure they could bend those as well, but it's just going to make the entire process more expensive by having to use custom circuit boards.
Also, what radius do they bend them to? A bend that works for one application may not be a "one size fits all" solution for others.
That's what the straight bar brings to the table, it's universal. It may not be the ideal shape, but you can use it on everything.
For one, standard circuit boards are bendable (especially if you are only looking are a minor bend that would be possible for an aluminum extrusion)
If you are looking for a more extreme bend you can use individual boards for each LED.
A manufacturer can also specify pre-bend boards or a flexible matrix.
An alternative would be a multi section bar that would pivot at the front.