If you ever read "The Cathedral and the Bazaar"... Debian feels very far from this original vision, endless drama and politics. Similar to Gnome and Mozilla.
There was a proposal, disagreement, and a vote, which ruled in keeping the "which" command where it is for at least the next major version. "which" is in no danger of disappearing at the moment.
The discussion went approximately:
"`which` is nonstandard and doesn't always work the same. Maybe we should remove it and have everybody use `command -v` instead, which is standard. Also, in testing, I've added a deprecation notice to prepare for it."
"Let's have a vote to see. A lot of people use `which`, and that deprecation notice breaks some builds.
...
Vote says no. Remove the deprecation notice and leave `which` where it is for the next release"
Later, on Hacker News: "Debian might be removing "which"! Why are they doing this?"
Most of the commenters, it seems, never actually read the entire story.
It's stupid. An immense and completely unjustified waste of time. which(1) requires maintenance no more than once per decade. In terms of the amount of maintenance that which(1) requires, the entire debate took centuries' worth of the maintainer's time to settle, and much more of everyone else's time. The entire effort to get others to switch from which(1) will take untold amounts of _their_ time.
In conclusion: Debian couldn't care less about their users' time. No respect for the users.
I'm trying to make my real thoughts on this palpable. Idiotic doesn't even begin to cover it.
I think it may benefit to take a step back before assuming bad faith. The issue was (and still is) that "which" is not portable and it's difficult to detect what version you have installed.
Depraved indifference (we don't care how much this will annoy users) rather than bad faith. Given the lack of maintenance burden and the amount of stuff that would break in $bignum scripts, the idea that removing it was seriously even considered speaks volumes.
I'm not sure what "volumes" you're talking about. Those scripts already risk being broken and causing maintenance burden by depending on the non-standard behavior in the first place. If you actually had this specified in your dependencies then it would be easy to spot the necessary change and fix it.
Actually you may want to take a step back and read some of the comments, the behavior of "which" can be inconsistent even between two systems of the same distribution depending on what shell you are using.