From the pictures it looks like the cracks may only be in the stucco, and the underlying structural wall may be unaffected. It's hard to tell without actually inspecting the wall, but my guess is that these cracks are only skin deep. However, you will want to treat them to prevent them from spreading.
Here are some excerpts from the article.
All buildings are subjected to a
variety of stresses in various forms
and this stress is often transferred
to the plaster stucco membrane.
Stucco
is not and never was intended to be a
structural material.
Cement stucco is
a relatively thin, brittle shell over
a framed structure and can crack if
the stresses are transferred and
overcome the strength of the plaster
membrane.
SHRINKAGE STRESS
All Portland cement
shrinks as it cures. Controlling and
minimizing that shrinkage is critical
to minimizing cracks
Shrinkage cracking
tends to have a map-like cracking
pattern.
OUTSIDE SOURCES
Structural loads,
lateral force racking, thermal
changes, wind, lumber shrinkage and
seismic events are all examples of
outside sources of stress.
HOW HARMFUL IS A HAIRLINE CRACK?
a hairline
crack does not automatically mean the
stucco is faulty, failing or will not
function for the service life of the
building.
MAKING REPAIRS
Once the decision is made to make
repairs, there are several options.
Option 1: Treat the joint with the
same finish material.
Option 2: Paint the wall or ceiling
after treating the crack with an
acrylic paint or paint designed for
stucco.
Option 3: An elastomeric paint
coating.
Option 4: Recoat the wall from
architectural break to architectural
break with the same finish material.
Option 5: A new basecoat and mesh over
the wall area.
Best Answer
Just from the pictures it looks like a bad install. The cracks look like they are rolled. They aren't on any parts of the structure where there are two joints meeting or any sort of weak point. They are basically right in the middle of a wood framed exterior.
[Remember this advice is just based on me looking at a couple pictures and from what you said about inspection. I am thinking that your inspector really looked hard on the other side of these cracks and found nothing. They don't seem structural (but could be). So I am really relying on your inspector doing a thorough job.]
How would I approach this? First @Jack's comments are correct. It looks like EIFS. So I would get a couple of EIFS/Stucco installers out to get quotes on what they think is wrong and how to correct. I am going to guess that there were installation steps or materials skipped. A total guess would be that they left no expansion gaps for the insulation and that the insulation expanded and pushed out the finish layer.
If the installers say something similar and quote you something now you have a dilemma. This doesn't seem to be a huge thing. But given they made a mistake here, it was probably made everywhere. This is probably the first issue since it is the biggest continuous exterior wall.
So I would go into this with the thinking that if it is an install issue then you might have more. I would also figure out the age of the install. If it is less than 5 years old I would think this waves can pop up everywhere. If it is 10-15 years old I would be less concerned. But really it looks to me to be a cosmetic issue and if you are the type of person that doesn't care about that as much, it really isn't a big deal. Really this is why stucco and EIFS has more issues in temperate climates and is found more in the far south (or Spain and France).