With the changes from https://github.com/Ultimaker/Cura/pull/15692 logic regarding the exclude materials printer setting changed. It has never worked properly before. Now that it works properly again a ton of materials were excluded that were never intended to be excluded.
As we can never be sure if an exclude material was intended or not we decided to be pretty agressive in removing exclude materials. This way the behavior is closed to the behavior prior to the exclude material fix.
There was one case were we decide to leave an exclude material in. If a printer has a material diameter of `175` *and* the material would specifically specify the `175` substring (e.g. `dsm_arnitel2045_175`). When this is the case we were pretty certain it was intended to exclude this material.
CURA-10599
A lot was changed in support. The short of it is that we now think towers should be on by default, but aren't _completely_ certain about it. It makes more sense to do make this change before the beta rather than just before stable, so we have a chance to revert should it prove disastrous.
