Why do the tubes in the Seattle Space Needle Architecture set need to be cut? I just received the Seattle Space Needle from the Architecture series. There are tubes that the builder is required to cut to a certain length for the model.  This is the first time I've encountered tubes in a LEGO model.  Are the tubes made only one size making it normal to have to cut them to use them?  I was wondering why the tubes were not manufactured to the correct size instead of having the builder cut them.
This happens in Technic models as well, at least for pneumatics tubes. I would tend to assume it's a simple production issue or simplification - as this requires less work from LEGO.

That way, they only need one length of tube per model, instead of having one part ID for each of length of tube. Considering LEGO wants to control its number of elements currently in production (it's not infinite), this makes sense.