Okay! You're old fashioned!
But you're right in part too- they're a better replacement for the submachinegun or carbine than a real rifle, and the possibilities of the design have never been realized in any model I've yet handled or used. Ambidextrous downward ejectiuon is needed, along with a sighting arrangement that allows use from either the right or left shoulder without adjustment.
To date I've used and carried the French FA-MAS F1 [and the F2 version looks like a real improvement with just a minimum of refinement] and the British L96A1/ SA80- and again, the latest A2 versions by Heckler and Koch seem to be even better upgrades. They're not quite there yet, but they're getting closer.
I'm looking forward to playing with some of the Russian bullpup Kalishnikov designs, particularly the Russian OC-14 *Groza* and the bullpupped SVU version of the venerable SVD sniper's rifle, and to a more extensive wringout of the Israeli TAVOR than the short intro I've so far received.
The South African Vektor CR21 is another I hope I get a chance to work with soon. But I've got something of my own in the works, too. And the magazine doesn't interfere with a good prone position in the least- no more than a Bren gun's does....
-archy-/-