Of course the receiver market is "not declining as much as might be expected."!
I have my Yamaha AV amp connected to a pair of Q-Acoustics Q2050i speakers and a Tannoy subwoofer. A soundbar simply cannot create a genuine (as recorded) soundstage and smooth frequency response of a properly positioned stereo speaker setup. What's more, you're not going to get anyone with an interest in music using a soundbar to play their music - proper stereo speakers and a potent AV amp (that serve for both audio and TV use) provides the best possible solution.
Soundbars remain a necessarily compact solution for flat TV's that can never accommodate the correctly sized cavities for proper loudspeaker sound reproduction, and/or for rooms that cannot accommodate proper loudspeakers.