[marcosdumay]

IMO, graphical languages should have graphical merge tools. You can't expect the text to be mergeable, but it's not enough reason to refuse file diffing as a concept.

The problem is that graphical tools are usually large, proprietary software made with the explicit purpose of locking people into an entire ecosystem. Diffing is a small specialized operation that enables portability and interoperability between ecosystems, so tool creators actively avoid those.