Does Sigma/Tamron offer a 70-200 2.8 that performs as well as the Canon? Nope. How bout a 24-70? 2.8? Hardly. The cost (R&D, tooling, marketing, advertising etc.) of the 7D was most likely recovered about 12-18 months into the run. The new 7D2 needs all these things so yes, Canon will continue to produce this amazing camera to fund better products.
Answer is yes! Take a look at Tamron SP 24-70 2.8 which is direct competitor of Canon EF 24-70 2.8L MKII. Tamron's quality is slighty less worse than Canon's, however, Tamron has stabilisation. Also, try Tamron SP 70-200 2.8 which quality is very good as well. Both Tamron lenses are much cheaper. That why I told that third party manufacturers are taking quite significant part of Canon's lens market.
Sorry, but as neuro said, and I have observed comparing them for my photography business, Canon won every time. Shooting test charts, working, etc. The softness of the tamron 70-200 @ 200 is laughable at best and ruined a Kayaking session I used it for.
Also, most people don't follow what the currency markets do so the de-valuation is not why they want lower prices. They want lower prices because that is human nature.
Here you are also wrong. Everybody is looking what competitors are doing. If competitors can offer similar quality products for much lower price that means that Canon is doing something wrong: 1) Maybe they have issues in supply chain 2) Maybe they invest very heavily into R&D (which is not the case) 3) Using Yen's devaluation for their own profit (when competitors using this factor for lowering prices and increasing market share). Also, if you are not well educated and do not understand how changes in currencies rates affect different economies, please do not comment on matters which you do not understand (by the way, are you American? )
People look at what their competition does because of, wait for it, Human nature. Competitors are not offering similar quality, they are offering lower quality cheaper equipment. Supply chain? Nope, other then the 600 f/4 II and 400 f/2.8 II but they are specialty lenses. R&D? Canon does not invest in this? Are you daft? Did you read what I posted about the 400 f/2.8? Optically better, lighter weight, faster focus, power assist focus for people doing movie related things, the list goes on. Canon 24-70 II, MUCH better sealing, Lighter, better IQ (better then some primes), a Lock switch so the lens barrel stays in place (my personal fav), much better overall design compared to the Mk1.
Not that it matters, but I have a Masters Degree in Mechanical Engineering, minors in photography and Material sciences, I read the economist every week and follow the currency markets closely as my job is tied very close to these markets. So yes, it is not because of the markets it is human nature that people want things at lower prices.
Mirror-less will not replace DLSR any time soon. Try shooting a moving object with a mirror-less.
Here you might be wrong as well. Take a look how quckly digital cameras overtook film cameras. The same could happen with DSLRs and mirrorless cameras. You are stating your very subjective opinion based on emotions and not facts.
I hope that I clearly explained everything to you.
Focus is the issue here, not film vs digital. I have an EOS M (honestly, love it for travel) and have tried to toss my 500 f/4 II on it for birding, its terrible, even if the bird is sitting still. Toss the 1Dx on and I nail focus 99% of the time. Mirror-less and SLR use two entirely different methods of focus at current. http://en.wikipedia.org/wiki/Autofocus
Read this and it should explain what your looking for.