+1 on Rudolf's comments regarding fear of coloration from signal chain and drivers. If you design a system and measure its response and it is flat and the impulse response looks good, what other sources of coloration are there? When people go back to vinyl turntables because they want analog source that is not colored by digital trickery maybe thy forget that phono preamps and records all have built in RIAA EQ profile coloring and uncoloring applied via analog means? Even pro reel to reel tape players have built in compensation that hopes to uncolor the effects of the transport and pickup head.
More accurate, I think, to say it's a decision "made by the room". One way or another (absorption at the wall, at the driver, or by elimination the rear tweeter altogether) there has to be some suppression of high frequency reflection from the front wall.
I agree that the baffle is the proper instrument of pattern control, and I'm firmly in the "narrow baffle" camp, but once wavelength gets below 10-15cm. narrowing the baffle becomes progressively more difficult and the rear radiation from most cone drivers just becomes an awful mess. And there's a lot of "wiggle room", where selectively absorbing the higher frequency radiation doesn't compromise baffle control (of radiation pattern) at the lower frequencies where it does work. It's a balancing act between driver, baffle, room and selective absorption . . . all are involved, and it's a mistake, I think, to abandon any tool in pursuit of some "design purity".
In my listening room (which is very good for dipoles) a rear tweeter is, um, "not indicated" . . . and fully symmetrical dipole radiators (ribbon or planar) require either an overall roll off (not the best solution) or a reduction of rear output by selective absorption. What sounds best is flat-on-axis coupled with a falling power response (above about 2kHz.), and controlling the back wave is an easy and effective way to get that.
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What I have discovered that I don't like my box without some absorption behind it so I think this means that I don't like the sound of a dipole speaker. But it does sound a lot better without being a closed box and it isn't just the bass that I'm listening to but also the mid range that is affected by this.
I think this whole discussion, which i applaud, goes to the key point of the speaker + room combination. A speaker designer can't really make a one size fits all solution. However a diy builder or smart speaker buyer can select to design for the room intended, or even build the room itself if the budget allows.
And heresy of heresies: OB's are generally way to big for the rooms installed to work as dipoles, and dipoles required a lot of room behind them to operate correctly, and large open-backed speakers in too small a room sound weird. Boxed speakers do not have to sound boxy. All of which is why I don't to OB's.
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