Yeah. What lunatic continues to buy gear they hate?
you have not read, what he wrote. He is using multiple Canon bodies for stills and video. Out in the wild.
The last thing I'd want out there is a body from another manufaturer, with different user interface, different sensor characteristics, different batteries, etc. ... how about you?
If my livelihood depended on it, I would.
I might still do that in part (even though I do this for a hobby). I did not like the WA lenses of Canon so I might just pick up a used D800 (sell quite cheap these days) and the 14-24.
It's such a common perception that pros NEED the best cameras. In most cases they don't, infact they get by using quite humble equipment. The things which amatures prize, are not the same things which pros need or desire. MP count is typically very low on our lists. Reliability and build generally are they highest factors. A client usually doesn't care if a quality image is 18mp or 36mp, as long as it's the image they want, it's sharp and clean.
I don't think you read the posts carefully enough. The question here was not if a PRO needs the best camera. AvTvM's question was that why would you buy into a different system? My view is, why not? Learning a new system is by far a better option than buying gear you hate and rant about in internet forums.
Coming to your post, it all depends on what you shoot. Maybe a wedding shooter can get by with the previous generation equipment but wildlife / bird shooters do usually buy the best and the latest equipment to come out with standout photos, or do you mean to suggest that a 1DX with a 600mm f/4 offers no improvement at all?
BTW, isn't it funny how some Pros come out citing humble equipment when they themselves -
use a 35mm f1.4 L, 24mm f1.4 II L and 16-35IIL day in day out professionally and have for many years.
I shouldn't have to read posts carefully if they are written out clearly enough....tricky posts are the mandate of trolls...
Yes I have a lot of high end kit. But I also serve a lot of different genres in my professional guise. I shoot a lot of weddings, landscapes and a bit of wildlife (although the latter is more for fun). All three genres generally need a different approach to kit requirements. For weddings, I generally use fast primes. Of which my 35L and 85L are my main lenses. My landscape work needs xoom versatility, so my 16-35IIL, 24-70L and 70-200L are mostly used in that context. My wildlife protfolio sports a 70-200L, converters and a 400L. So 2-3 lenses per genre.
Camera wise, I use the same 5DIII for all three and they are working well for me. On my last trip to the Saltee Islands, were a number of photographers with the new 500mm f4 L IS II mated to 1Dx cameras. A very capable and light combo. I look my heavy 400L and looked quite tired for most of the time. There were a few guys there with the new 300mm f2.8 LIS II and 60D/ 70D combos...fairly modest gear for this genre but I have to say the imagery from these cameras and lens combo was nearly as good as my 400L...so one has to wonder. It was quite a low spend (from nothing), light and very capable. The 70D with a 300mm f2.8 had a nice reach and with a 1.4x or 2x tc easily matched my 400L on a 5DIII for framing (with converters). He eyed the slight quality and DOF difference beween my kit and his enviously, I looked over his kit with an envious eye for the weight and size considerations!
So choosing humble gear is relative and very genre specific. Ultimately it's the photos which matter and where a photorgapher is prepared to draw the line and put their compromise.