Hmmm... yes.

Pretty much; if you weren't a Nintendo diehard there was really no reason to buy such an unappealing product.

Like me, basically; someone who loves Nintendo's games so much they can't go without them.

I bought one and I certainly am not a Nintendo diehard... so no...

I think Nintendo diehards were one group.  The other big group was kids.  Nintendo home consoles are always loved by kids.  (Not sure if you consider kids to also be Nintendo diehards.) 

I wasn't going to get a Wii U, but my daughter kept begging and gave me big, sad puppy-dog eyes.  So I caved and bought a Wii U.  It was the successor to the Wii. so I understand why she wanted one.  Nintendo consoles are always popular with kids, but the exceptional ones manage to be popular with everyone else too.

I disagree with premise that "Diehards" giving it a pass is what led to poor sales. Large sales volume comes from non-"diehards".

But if only the Diehards of the Diehards bought Wii U... Can we say Wii U is the hardest core of hardcore gaming consoles?

If "Diehard" means anything, I would think Diehards would stand their ground even when a platform should be dead by normal reckoning.

I bought mine about a year after release. I loved it, the two screen gaming was a great idea, and the off TV play, and I really liked Miiverse (RIP).

It was hard at the time seeing it doing so badly, but it did band us Nintendo fans together and meant I played games I wouldn't normally as there were so few releases. I thought it was a great concept, perhaps not executed as well as it could have been.

Really pleased the switch is doing well, a natural evolution of the Wii U concept.

Just like some others, I'm not a Nintendo diehard and I still bought one during the first months of its life for the announced games and the prospect of others that could come.

I also have to say that, if I had waited a bit more, I would have probably ended not buying it at all.

Not even all of the die hard. Just the ones that knew it was a new device and not a pro Wii. Such a terrible name. If Wii U had been named anything else, it's sales would have been much higher. One of my best friends growing up, a guy who played more video games than I did on a multitude of devices, was unaware it was a new device rather than just a better Wii. He is absolutely hardcore, so if he didn't know that tells you how much the regular gamers didn't.