I think the small applications with narrow focus you find used on the
commandline are simply a good match for the Linux audio ecosystem with
its many one-man part-time projects.
On the other hand there's a strong desire among users and developers
for applications with a rich feature set and often also a pretty
graphical interface. It can of course be done, even by just one man,
but it takes a lot of time, vast depth and breadth of skill and
dedication and a stable list of features for both the project itself
and the libraries involved to make such applications *and polish them
to professional standards*.
I watch this ambition not without sympathy, but also not without
occasionally speculating what the Linux audio landscape might look
like with less lofty and more UNIX-shaped goals.