Someone like, say, Michael Chrighton, or Freeman Dyson, is vilified for speaking out against AGW, especially given their lack of expertise in climatology. Al Gore, however, is treated like a hero, despite having not only no experience in climatology, but his total lack of scientific expertise, because he espouses an opinion for which there is scientific consensus.

Uh, yeah?

So Al Gore is acting (to a degree) as a spokesperson for the scientific consensus.
(Consensus based on repeatable results, not just "we all agree with that guy", by the way.)

Anyone taking a contrary position to the scientific consensus will need to have some fairly impressive scientific results backing them up, if they want to claim the majority of climatologists working in their own specialist field have got it all wrong. If you haven't got some real compelling research, and it's not even your field of expertise, then you run the risk of looking like a crank.

(I know nobody will read this being 3 days later, but I'll reply for completeness' sake.)

Lets continue to compare and contrast things that either show that you don't like how photoshop implemented a feature, or how you cannot find a feature vs. how GIMP is missing features completely.

That was kind of my point in the original reply. Most (certainly not all, but most) complaints about Gimp relate to differences in implementation rather than complete absence of capability. I knew my questions about Photoshop must have had answers (thanks to everyone who replied with tips); I was just highlighting that they weren't obvious or were frustrating to me, having come from a different application.

Gimp, as it stands, is unsuitable for professional print work. That's undeniable due to lack of CMYK and 16-bit channel support.
But there's plenty of image editing that isn't destined for print publishing.

It also lacks the polish of Photoshop, and it's missing some useful tools of convenience. (Filter layers seem to be a biggie.)
But for the most part it's capable of producing the same results.
Given a specific image editing task, I'm confident a proficient Gimp user could produce an equivalent result to a proficient Photoshop user.