Andrew Gideon wrote
Where I flew too had a limit on soloing students with respect to weather.
It was probably something of the sort you're describing, or perhaps even a
little more strict (I seem to recall 5 kts xwind).

But, after taking the checkride, I was immediately permitted to fly in MVFR.
That seems silly to me.

Silly is an awfully mild word. I would say dangerous.

This happens for one of two reasons. First, some instructors are more
concerned with liability (either civil or FAA action) than proper
training. These instructors will have 'boilerplate' restrictions for
students, along the lines you've mentioned. The whole idea is wrong.

Properly used, restrictions are always tailored to the student's
skills and experience. If he hasn't really figured out crosswinds
yet, he soloes with a crosswind limit. Once he gets to the point
where he can handle normal conditions AND has learned to recognize
when he's in over his head and needs to do something else (go around
and try again or even go to a different runway, possibly at another
airport) the crosswind restriction goes away. That doesn't mean he
can handle any amount of crosswind - nobody can - but it means he is
competent to make his own decisions. The same applies to visibility -
if he hasn't been exposed to MVFR (or hasn't learned to figure out
where his limits are) he soloes with a visibility restriction. Once
he has shown the ability to handle MVFR, and to recognize when it's
just too marginal, the restriction goes away. Again, that doesn't
mean he can deal with a mile vis under all conditions - just that he's
now capable of making his own decisions. By the time he goes for the
checkride, the restrictions all need to go away - if he hasn't figured
out what he can handle, he's not ready to be taking passengers and
exposing them to the risk. And yes, this means dual AND solo training
in strong gusty crosswinds and MVFR.

Sometimes the restrictions are set by the flight school. This makes a
statement. The statement is "We don't trust our instructors'
judgment, but we are not going to fire them because it's more
important to keep the planes flying than it is to provide quality
training." Pretty sad, really. It ensures the student will be
shortchanged, and will have to figure this stuff out on his own.

I think that there should be a progression to
"lower" weather, with much attention given - as others here have posted -
to *why* and *what comes next* (ie. are clouds dropping or rising).

I think you are absolutely 100% right, and that's how I teach. There
are a few flight schools where I am welcome to teach, but not many.
One of those flight schools is run by an airline pilot who fired his
only full-time instructor because he felt quality instruction was not
being provided. This was at a time when instructors were hard to come
by, and you can bet there were financial consequences.

Of course, I expect that most of us have followed that progression. But why
no "program" to support this?

Because half the instructors out there are not competent to teach in
that progression, and it's not required to get a PPL. PTS does not
stand for 'Perfect Training Syllabus' but that's how it's often used.

Michael