In LAME 3.97 alphas it sets the -b to 32.

First why?

Second, why does the pinned post in the forum say it is 128.

And third, what does it mean exactly to force -b 128 or -b 192? They produce the same file size still even though that sets the lowest bitrate limit?

Lastly, why would I want 32 over say 128 or 192? I read here that going below 128 in vbr is bad.

I know everything says don't mess with the defaults, but I don't get -b 32 default.

edit: fixed spelling error

But you would get a -b 128 default?
It is likely that you can not really provide rational yourself about a -b 128 as default, so why do you care about -b 32?

I do not mean that you should not ask questions, but I am wondering about the need to often question about default settings.

Regarding why lowering the minimal bitrate:
*In vbr-new, this never produced a low limit anyway, due to the way vbr-new works. Thus in this mode the previous low limit was pure placebo.
*In vbr-old, it seems that with current tunings, the lower limit can now be lowered.

Using -b 128 was a kludge anyway, so if we can remove it, then let's do it. Using -b 128 allows to not be limited to 128kbps for near mono recordings, as an example.

Well first, I clearly do not fully understand the -b stuff, hence my question. But I do have a rational for asking in the first place, it's that 128 is better than 32, and 192 is better than both (from a quality point, not size). So therefore I wonder why it is 32 default now and not before. And also wonder how exactly it is bad to change it.

VBR allocation of frames is not necessary perfect. There's always a possibility of wrong estimation of the real need in bitrate. As a consequence, the allocated bitrate could be too low, and leading to audible distortion or annoying artefact. A bad but working solution for this issue is too fix a minimum bitrate value as floor. With previous LAME versions, the VBR model wasn't apparently considered as safe enough to let him a total freedom. --preset standard/extreme was therefore not allowed to encode below 128 kbps.
This lack of security is now fixed apparently. I've tried to encode extreme samples with -b32 switch and LAME 3.97 alpha, and I couldn't trigger any artefact or additionnal distortion due to the presence of frames at 96 kbps or below. Nobody has reported on problem sample as far as I know. Therefore, keeping the previous limitation (-b128) is not a necessity anymore.

If you only consider quality, then if you use mp3 you should use 320kbps cbr.
However, most of the people also care about size, thus allowing a lower bitrate is benific for them.
Everything is a matter of trade-off with lossy encoders.