I think you might be misreading the intent behind those statements in one of two ways:

1) Capability != Experience. Gimp is capable of doing about what Photoshop can do for photographers but with a much, much worse experience.

2) Photographers aren't the only Photoshop users and Gimp's shortcomings are much more consequential for, say, Graphic Designers. Comparing Gimp's typesetting tools to Photoshop's is like comparing a screwdriver to a fully-stocked workshop. Since those features generally aren't on photographers radars, let alone in their regular workflow, I didn't include them.