I think Microsoft was always planning the Scorpio but they didn't anticipate the PS4 Pro, hence the rushed E3 announcement. 

What you want is a keyboard with pressure sensitive keys. Roccat has one out with QEWASD keys that are pressure sensitive.

With that in mind, you are always free to use a console controller on the PC, but personally I prefer not to, the mouse is a venerable piece of hardware that can't be topped by it's speed and precision.

A lot of people are buying 4k TVS (adoption faster than 1080p) and chances are they are going to want a console that utilizes a 4k tv. People make me laugh here with the PC argument. Most games bought on xbox one and ps4 are games found on the PC that can run on PC with better graphics/fps. However, guess what people still buy the console to play those games.

So, If you have a giant garden that gives you a huge harvest, but you can only carry two things at a time, then you will need to increase your expenses in tools and workers in order to take advantage of the full produce. Eventually as the garden becomes bigger and produce increases so does the production costs until say costs become higher than the potential profits from your limited costumer base... and... whatever, still bestest analogies evah.

The Scorpio will not be able to handle triple A games at 60fps and 4K resolution, you need at least 7 TFlops for that. The scorpio will not hurt the PS4 sales wise, sony has better exclusives and the momentum to keep outselling them. The Switch is actually exciting and interesting and will have mainstream appeal.

Consoles are dying, all of them. No matter how good the PS4 is selling, the combined 8th gen consoles won't outsell Wii + ps3 + 360. On the handheld field we have 3DS selling half of what DS sold and Vita being Sony's last handheld.

The reason why console gaming is dying is because of practices like charging to play online and very expensive games. PC on the other hand is growing more and more because even if you are not much of a gamer you'll own a PC at some point even if it's a laptop that you just use to play LOL, and because of that kind of games PC is now the platform with the most users by far and that moves larger quantities of money (i mean LOL alone has a 100 million players). Also games being cheaper and online not requiring a monthly fee helps a lot. 

I use a 360 controller for FIFA, but that's it. I don't really play racing games on PC since I enjoy playing them on a huge screen and I mostly want to play Gran Turismo (which isn't on PC, as we know). A steering wheel beats everything though, and those are just as good on PC as anything else.

Oh, I also use the controller for emulator titles like FFXII and HD remake of FFX.

But I agree with what you're saying; there's no reason to replace the mouse and keyboard and while consoles have gone through fad after fad and a multitude of button layouts, triggers, sticks, turbo modes, motion controls, IR sensors, gyro, gimmicky touch and everything in between, mouse and keyboard remains much the same in its basic use and input. The major change that I can think of is programmable keys and things like DPi settings and sniper buttons. There simply is nothing that beats a modern gaming mouse with a nice, mechanical keyboard (using a Logitech G502 mouse and a Razer Ultimate Blackwidow Stealth myself).

The indie scene was better before it hit consoles, it was free!

That's one of the things that stinged from the Switch's reveal, having to pay for online. 

Well maybe it will not sell on release, but don't you think they intend to replace the current X1 with it?, it will inherit all it's gaming collection old & new

The focus on 4K is a bit premature, but great 1080p60fps would be worth the upgrade for many users. If I had to buy a console now I would go for the more powerful system.