Naming things is truly one of the two hardest problems in software engineering.

The GIMP has been around under that name for going on 20 years. Its user base has grown exponentially worldwide, and the tool kit itself is standing on the brink of a quantum leap in capabilities. I see no signs that its name, which has positive brand recognition across a very large community of users, has held back the GIMP's market penetration in the least. At this time, a name change would be actively harmful to long established organic promotion that works very well.

Any "quantum leap in capabilities" is strictly inconsequential to naming, I hate nerds.