I always wanted one of these, just never had the justification for the 'full' setup.
I think the bigger issue affecting marketability is that in simple setups these just aren't needed. Streaming has led to an even greater simplification too. Right now, the only time I need a remote
other than the remote I use for the streaming device hooked up to a TV is if I need to use another input. For the living room TV, that's the Blu-ray player (like, rare), and for the bedroom, that's switching the HDMI input for laptop use, because the receiver is so old that it adds hundreds of milliseconds of input lag. Fine for streaming, no go for desktop

.
And in both cases it's a matter of using just one other remote.
Now, for a more 'integrated' setup, say with gaming consoles and the like, multiple streaming boxes, dedicated HTPC, and so on (I guess?), I can see the value of these, but I think the broad market appeal just isn't there. HDCP has covered most of what Logitech was doing with their Harmony series pretty well.
Last, it's Logitech. I won't say that they have a
bad reputation, because they don't, and they do make many quality products, but they also do make 'cheap' products and products that fail where they shouldn't. And that's regardless of product tier. I think it's also important to keep the primary customer base for these in mind: most folks just have zero clue when it comes to home theater stuff and if they have a problem, which they almost certainly can't properly articulate, they're also almost certainly not looking to
Logitech to provide the solution.
Which is unfortunate I think!