Uh, you can have multiple users with different IDS on the same Wii U. 

I'm not too sure about the exact number, but I do know that at least 80% of my digital WiiU games are VC games!

I don't mean that, I mean that I can only have my NNID on one Wii U and one 3DS at the same time. Thus, if I purchase a game, it is tied to one console, with no way of transferring it other than the link or sending it to Nintendo. With the PS3/360, you can have the same game downloaded on multiple systems, and if a console breaks, you can just buy a new one and sign in to access your games, no need to send the console to Nintendo.

I've bought loads - 15 VC games, 15 digital/indie titles and 7 digital/retail titles. All sitting on my 500GB hard drive I got a while back for a bargain £32.

But you can transfer between Wii Us now and 3DSes. I really find no reason to have multiple IDs anyways. What you are complaining about is content locked items. Which is understandable, but pointless to complain about. Nintendo is practically rushing in to what Sony and MS has now. Besides, your content on your console is also tied to a NNID that you used to purchase it. This is why they say (multiple times) don't wipe your purchases from your 3DS because it will also effect the Wii U. 

You have no need, but as a person with 2 3DSs, I do. 

And my content feels like it belongs more to Nintendo than me. To recover my purchases in case my console breaks or gets stolen, I have to send the console or the police notification to Nintendo, which is complete bullshit. I want to be able to access my content from any device instantly, not the horrible system they have going now where they control all your data on your consoles.

Why do you have 2 3DSes is my question? Is one for the toilet and the rest for everywhere else? On a side note, Sony and MS both control all the data on your consoles too. This is the sad reality of digital offerings. Hell even Valve has the right to revoke your licenses for all your Steam games even though you bought them. This is why many people still purchase digital items on Nintendo products. It doesn't matter. I'd rather all physical, but that's never going to happen. 

Why do you care why I have two 3DSs? The point is that I do. (And if you really must know, I have a launch regular 3DS and I bought an XL recently).

And neither Valve, Sony, or Microsoft dictate which consoloes your purchases can be tied to. All of them allow you to use your purchases on different consoles, as long as your account is connected to the console. 

Nintendo only lets you have your account on one console at a time, and forces people to go through their arduous repair transfer if the console needs to be replaced. If you don't want to or can't go through with such a repair, you're out of luck, all your files are forever gone. If I lost my 3DS, I can't ever get those digital games back, whereas if I lost my PS Vita I can easily get another one and just redownload my collection.

Sony, Microsoft, and Steam are much more flexible with their digital offerings. They control all the content (Newflash: they control your physical content too, you really think just because you have the disc you own the game? You only own the physical media, not the game itself. Sony/Microsoft/Nintendo can easily cancel your ability to play the game on a console if they wanted to. Don't believe me? Read your EULA.), but not to the point where they breath down your back like Nintendo does.

In total- 129 games in my library are digital. 65 vc, 52 indie, and the others are digital copies of retail games from eshop.

Again, why complain. Besides you bought a 3DS XL and did not transfer your normal 3DS to it. That's your fault, not Nintendo's. And yes I did know they control physical offerings aswell. you didn't need to be rude about stating it also.