So... after quite some time new functionalities aimed to generic players were added.
Placing buttons on horizontal surfaces is cool and useful but they also made life easier for anyone who wants to regulate the strength of a redstone signal.
Until now you had to use comparators coming out of containers, using different items and stacks to switch between a strength of 0 to 15 and, once set, the only way to know how much power you got was to add a monitor system of some sort (or manually counting the items and remembering the conversion table).
Now you can attach a comparator to an Item Frame and rotate the item inside the frame to regulate the signal.
They only offer 8 positions but they can be read just by looking directly at the item orientation.
Now, if they were to also add a way to monitor the strength of an incoming signal directly with 1 single block we could make MUCH more compact visual counters, reducing the footprint by at least a good half.
Of course they could more simply add a proper counter block but I guess they're not inclined to do so, for reasons I can't quite understand.
Instead they find reasonable to add features that no one with a sane mind would make available on a public server, ever (aka Command Blocks). Oh well