It's not always best to argue on principles. Sometimes you have to argue on reality. Yes, you do have to pay for an accessory, however, that accessory is very cheap (no offense if you have a low paying job). To many of us, especially those of us who are successful and run businesses, time is money. I don't get to go shooting whenever I want. I have opportunities, and they come and go. I'd rather spend a bit of money, and keep the lens at home, than send it in to get an update and wait a week or several weeks.
Furthermore, each time you ship something, you take a risk of it being misplaced, stolen, lost, or damaged. While you may get compensated for such an occurrence, it's just another added headache. Another added reason why being able to plop your lens onto a dock and update the firmware in a couple of minutes, even if it does cost ~$50, is so convenient.
As one who runs a successful business, which MkII super telephoto lens(es) do you own? (No offense if your business isn't successful enough for you to afford one.) Were they affected, and if so what was the turnaround time for Canon to update the firmware?
As I stated, my 600/4L IS II came with the updated firmware; I ordered the lens soon after its release, before the original advisory, but I received it after the advisory was issued. Given the timing, I expect there weren't too many affected lenses, especially the 500/600 II since they lagged and initial availability was limited.
To date, Canon has issued only 5 lens firmware updates. Four of them are covered by this advisory, the other I referred to above, which was available for download and application via camera body.
Many people choose Sigma lenses as a more economical option, particularly since the supertele lenses and many other high-end OEM lenses are so expensive. Since 3rd parties have to reverse engineer Canon's communication/AF/etc. protocols, changes implemented by Canon can (and have in the past on many occasions) affect compatibility with 3rd party lenses. It's good that Sigma offers the dock, to allow users to correct those problems. Of course, users with Sigma lenses that fail to maintain compatibility with a new Canon body or firmware update can look forward to weeks or possibly months for Sigma to release a fix that can be applied via that inexpensive dock, but I'm sure you've considered the effect that might have on productivity.