Hi Mekkablue,
I couldn’t agree more with trashing old paradigms and I must admit that you guys did an amazing job by doing so. So don’t get me wrong, I think Glyphs is truly wonderful.
But old is not always bad and new is not always better. And I can think of no paradigm in which giving false visual feedback is a good thing.
This is only true when dragging a handle. When applying a transformation to a handle you get a really really bad curve and that shouldn’t be possible with a smooth node.
Making good curves is the job of the designer and the software should help him/her do that. This node behaviour is definitely not helping. It’s even counterproductive. It’s a flaw in an otherwise brilliant piece of software.
And looking at the Fontographer screendumps it turns out Glyphs doesn’t have to guess at all. All it needs to do is rotate the handles in equal amounts around the on curve point until the angle between them is 180°. The lengths of the handles can remain as they were.
In case of a tangent point the handles need to point exactly opposite to the neighbouring nodes. Makes perfect rational sense, no guessing.
Maybe you could make us both happy and let the user decide in the preferences which behaviour he prefers.