You must not be watching closely enough
Not all of the lenses are a good deal (like some of the low end lenses, kit lenses, etc), but there are some incredible deals on L glass if you can catch them in stock during a 15-20% off sale.
I did catch a good price on a 600 ex-rt.
The only lens on my list is a 24 ts-e ii.
It shows as in stock for me, but won't add to cart. You might be able to call them and get it if this looks like a good price to you. http://shop.usa.canon.com/shop/en/catalog/lenses-flashes/refurbished-lenses/ts-e-24mm-f35l-ii-refurbished
Keep trying. That happened to me last week with the 200 2.8 prime. I even emailed Canon Refurb, but before they could resolve it, the glitch seemed to clear up and I ordered immediately. Got it a few days later. Perfect as usual.
Interesting. But this sort of means a "refurb", is not really refurbished in the literal sense. I guess that's why so many of you like "refurbs", because they're essentially a new unit. However, with lenses, if they have been out in the wild, then they are bound to be exposed to dust in places Canon might not clean, true?
I was at a Canon Live Learning event earlier this month. They had a lot of lenses that I recognized as being consistently on the refurb list on a table for people to play with. I asked the Canon reps about the refurb store, they were vague about where all they get the lenses, but said that the ones they take around for events like this, etc., are one source. They did have a TS lens there and BTW they would not let anyone put on or remove a lens or put it on your own body. They did it for you and then handed you the body with lens attached. I saw them politely but firmly snatch the cameras away from people if anyone started to try to remove the lens.
Sometimes I do wonder if they "seed" the refurb store with new items occasionally. I also suspect that in a overseas shipping cargo with hundreds of lenses in it, there are always a certain percentage where the outside box gets bent or something similar and I wonder if they pull some of those out and rebox them in the white refurb boxes.
My guess is they get these from dozens of sources. Trade shows, dealer returned items, Live Learning events, boxes damaged in transit, CPS loaners, etc. From the condition of every item I've bought (and from the date code when Canon used to put codes on lenses) none of the items I bought could have been out in the field for long if ever.