[Nexus 5 Q&A, Help & Troubleshooting] TToTT:
Oddly enough, the very first questions you asked were answered by the post you were responding to...

Think about this... When you first got your device, went into developer settings and set it to MTP mode, and then plugged it into your computer, it did what? Installed correct, working drivers that allowed your device to communicate with Windows in MTP. So... Obviously there's no "removal of ability" by anyone, not Nexus, not Google, not ANYONE. The mere concept of removing that ability would be absolutely detrimental to the makers of both the device and it's operating system. So no, that's not what's happened...

At one point in time, your device worked with Windows if you merely let the correct drivers install (in MTP mode) when you first plugged it into your computer... So, what's been done since then? Chances are, you've done a number of things.... 1) Installed other drivers than those that came stock with your device. 2.) Updated the drivers in some mannor that did not correctly make the device and your computer communicate in MTP mode. 3.) Removed your device from the computer without clicking the "Safely Remove Hardware" notifaction, effectively causing compatibility issues. 4.) Installed an app that's meant to serve as a file browser/rooting tool/media transfer software, and in doing so, changed which drivers are being used to communicate with your device... Somewhere along the lines, you did one of these 4 options, and in doing so, you severed the device's expected MTP driver use.

Think of it like this... If you drive a car powered by gasoline, and you put diesel in the tank, do you think your car's gonna like it? Because that's what your issue is, somewhere you "put diesel" in the system, and your device/computer don't like it. Apparently, you and the guy that you're quoting have both failed to realize it's not Google's fault, it's not Nexus's fault, it's nobody's fault but your own (and, well, the fact that Windows is terrible about how to handle device drivers in many scenarios). All that guy did in his countless hours of work writing that code is make a work-around, and even by his own admition, one that might not work 100% of the time... Instead, what needs to be done isn't a work-around, it's a removal of the problem. And the problem is driver incompatiblity because somewhere in all the communications between your computer and device, the original driver has been corrupted/changed...

Now, most people are going to think "Ok, so an easy fix to that would just to update the driver again to something that works"... NOPE. Like I said before, Windows is terrible about handling things like this. Hypothetically (and realistically), you could actually install a perfect driver for your device, and it still wouldn't work right... This is because Windows carries over process details in a device regardless of what driver is being used... Using the car reference again, that's like expecting your car to now run using diesel because you've put it in the gas tank... If you're going to convert your car to run on diesel, you have to do more things to your car than merely adding diesel to your tank.... You can't use the same setup of parts in your car with the new fuel, but that's pretty much what updating/changing/installing different drivers on Windows is telling your computer to do... So it's simply not enough to only change your fuel in your car or drivers on your computer, that's not gonna work...

What you have to do is change all of what Windows knows about working with your device. Effectively, bringing your computer back to a point where it did get along with your Nexus in MTP mode... And you don't do that by installing more; you do that by removing all the excess junk driver info... And you can do that by following the guide in my signature...