Blender skeletal mesh scaled rotation

When importing skeletal mesh from blender (2.76b), rotating bone rotates corresponding mesh only for portion of angle.
It appears as stiff, scaled rotation:

It happens when import or export FBX scale is other than one, or when there is unapplied scale in blender.
Solution I’ve found for now is to apply scale to all objects in blender (Ctrl+A → Scale) and not to use export/import scale.

Can this be fixed or is it a blender-side problem?

No that is correct process. To avoid, always scale in object mode. Anytime you scale in edit mode it changes the physical scale parameters. When scaling in object mode it remains at 1.