If you instead had a full-turn periodicity, you would have substantially different properties for the curve shape. Several such curve primitives exist, you can use one of those if you want. This is one of the trade-offs involved in the choice of tool.
With this particular type of curve primitive, the primary way to change the spline is by adding and moving control points, not by trying to manually specify tangents. The latter should not be used for general shape design but should be seen as a specialty tool to support niche technical requirements (such as straight segment to curve interfaces), and tangent adjustments should be sparing because large tangent adjustments will create lumpy shapes.
> If you instead had a full-turn periodicity, you would have substantially different properties for the curve shape
We would have precisely the same effect on curve shape from a 360 degree control than with a wrapped 180 degree control, but have twice as much travel to adjust the outcome more finely.
The only thing difference I suggest is the control. Its the difference between:
effect = control_angle mod PI ,or
effect = control_angle / 2
When a full turn of the control produces a full cycle of effect a better ergonomic relationship might result.