That's it. I am utterly convinced it's possible with only things available now. None are easy to use, none make it easier to share with friends, none make it easier to organize or find or buy. I can't find any reason for this.

You know what the best ebook reader is that I've ever laid hands on? The e-ink one I installed Android on. In absolutely every way (except for the weird soft-buttons) it is a superior experience than the stock system.

The software is the problem here, not the hardware, and the software on every single one has been at best stagnant and poorly thought out.

Ah yes, that famous mass market requirement.

much less math / standard comp-sci notation or a third language

Even better.

eBook readers have been declining in sales because they can't offer the features that tablets can. Simple as that.

So my point is that I wonder whether the market is reaching a point where those who wanted to try an e-reader made the purchase and are happily using their Kindles and Nooks and the rest don't give a shit. I would be very interested to know what percentage of Kindle buyers are repeat customers or own one and are buying one for a relative. I'd bet it's high compared to tablets.

I don't understand this. My Kindle DX is fairly ancient at this point, but it seems to do OK with english-language books and some math texts as well. I really enjoy it.

Or is that because I bought it in Japan? The US model does not support Japanese text?