Interesting, thanks for the link! :)
but:
Fldigi supports it mainly because many Linux distributions are now integrating it with their desktops
Which isn't the same as saying "it's better than the alternatives". Sounds to me like this person is trying to make things easier for users and possibly himself (e.g not requiring dependencies on rarely-installed libraries/daemons, e.g jack). But that's not the same thing as building the best solution.
Question: does this software need care about latency? Because if it does then this person's opinion might carry some more weight, I'd be interested to know how they think pulseaudio compares with jack on those terms (hint: jack doesn't suck ass or waste my CPU time doing things which I can do in hardware). But I suspect that latency isn't really that much of a big deal with regard to this application, you're probably spending hundreds of milliseconds just waiting for the response from the other ham anyway, right?
And I wouldn't exactly call it a "recommendation":
Use PulseAudio if your Linux distro ships it, and you already have the pulseaudio daemon running
That's saying "use pulseaudio if you're already using it", and implies "You're probably using it, because you've probably upgraded your distro in the last few years and thus had it installed automatically, possibly without your knowledge". This is not the same as recommending pulseaudio. In fact it reinforces my earlier sentiment.
They do say that pulseaudio has "a few interesting features":
it can take care of the resampling and volume control for us,
ALSA can do that too. Or you could just get hardware that doesn't suck.
it can stream audio over the network
JACK (which this software also supports) can also do this, and it does a much better job of it than pulse.
it makes it easier to run multiple fldigi instances (all accessing the same sound card).
ALSA and dmix, or, again, decent hardware (for extra bonus points, go research what pulse does when you have multichannel hardware. Hint: software mixing, because apparently lennart knows better than creative labs).
it provides mixer controls for input and output audio streams
"man alsamixer"; JACK. Noticing a theme yet?
it remembers which hardware is used for each application it serves, and it remembers the mixer levels associated with that application
Yeah, I've read that it's supposed to do this, but I've never seen it actually do it on any system I've ever used. And I did try, ad nauseum. Strangely, the pulseaudio documentation doesn't (or at least didn't back when I cared) see fit to mention where this information is stored, so e.g trying to manually get a certain app to remember its volume or output to a certain device by e.g editing a config file (since it doesn't seem to remember it as advertised) wasn't something I could manage to do. And I tried, oh how I tried.
But maybe you should let him know how bad it is since you think he's on the wrong path
No, that's fine - it supports something other than pulseaudio, just like any sane piece of audio software does. If they want to tear their hair out messing with pulse then who am I to tell them otherwise?
Indeed, the page you linked to starts out with:
A few words about sound I/O on the PC. "You are in a maze of twisty little passages, all alike".
And, finally, the snark in me is forced to comment that "one" and "many" are not the same thing. If we're talking about software support, I think you'll find that ALSA is far FAR more widely used (I've said before and I'll say again: the best thing about pulse is that it can present itself as ALSA, discouraging development of pulseaudio-specific applications and ensuring that I don't switch back to windows and/or commit ritual suicide). And if we're talking pro-audio apps, where it really matters, JACK is king.
But thanks for playing! ;)