Wow, good catch.
Upvote for you!
For folks who don't know, in Windows a right click on image, and "Search Google for this image" is about as easy as can be.
One question, when did I ever say the 400 DO wasn't sharp or took TC's well? Because it reads to me like he is calling people that say those things idiots, and his images prove they are.
Nope, you said "horrible bokeh". There are several pictures in that post (and elsewhere on the internet) showing the bokeh of the lens. It is not, in any way, "horrible".
What he doesn't show you is stuff like this that demonstrates what DO do to bokeh and how they handle specular highlights, you might have noticed not one of Mr Morris' images has any specular highlights, did you wonder why? No, of course you didn't, you are too obtuse to do that.
No, its probably because it isn't actually a problem in real world shooting situations and you are blowing it way out of proportion. Bryan from The Digital Picture had this to say about it:
"The Canon EF 400mm f/4 DO IS USM Lens has been criticized for its poor specular highlight bokeh (OOF blur quality), but I have seldom encountered this problem. Specular highlights can have a target-appearance at worst - concentric circles instead of a smooth blur. I can't say I like the bokeh of this lens more than Canon's other 400mm Lenses, but the 400mm focal length combined with a relatively wide aperture can very nicely separate a subject from its background."
If you are happy to pay $6,500 for a lens that does that then I suspect you are the idiot, after buying them for that much many owners are happy to sell them for $3,500 to get rid of them, maybe they are the idiots.
One thing I will agree with you on is that I think the lens is too expensive and a new version isn't likely to be cheaper. It would be stellar if it was priced at about 2/3 or 1/2 of the 300 f2.8 IS II. One of the promises of DO technology is that it is easier to eliminate chromatic aberration (a huge problem with traditional optical designs lens manufacturers have struggled with for decades that, curiously, doesn't completely invalidate the entire technology...) so fluorite lens elements aren't needed for high end telephotos which should make them cheaper to manufacture but, well, Canon. *shrug*
One last thing - that photo you posted is pretty disingenuous. Were you just not going to mention that it was taken with the very different 70-300 f4-5.6 DO? Just going to allow that to be inferred by people who didn't bother to do a reverse GIS? The 70-300 DO exhibits far more problems than the 400 f4 DO and is reviewed a lot more harshly for a number of reasons related to its IQ. If you've got a sample that demonstrates the absolutely horrendous disaster that is the 400 f4 DO, I'm all eyes, but make sure its the 400 f4 DO and not that other lens.
Thanks, for killing another internet lie.
And no thanks for making me want the 400 DO even more
5D3, 5D2, Sony α6000, G16 | EF: SY14/2.8, V20/3.5, 28/2.8 IS, Ʃ35/1.4, 50/1.8, 50/1.8 STM, Ʃ50/1.4 EX, 100/2.8L IS Macro, 16-35/4L IS, 24-105/4L IS, 70-200/2.8L IS II, 1.4x II, 2.0x III, T28-300 VC PZD, 70-300L IS, Ʃ150-600 OS HSM S | E: SY12/2, 35/1.8 OSS, 16-70 ZA OSS, 55-210 OSS, SY300/6.3 ED UMC