I personally love this. I also don't want any Adobe AIR apps in the store. If it isn't written in Obj-C and compiled with Xcode, I don't want it. This includes X11 apps like GIMP too.
I don't _care_ what's in the Mac App Store. If it's decent, I'll use it.
If not, I won't. That doesn't mean I have a problem with the Mac
App Store, as long as the crazies that think we might eventually
be locked into it are wrong. There's a place for running what you
want, and there's also a place for those who want to get something
that's simple, inoffensive, politically correct, and problem-free.
My mom's got a clue (and a memory going back
to plugboards and punched cards); if she had a Mac, she wouldn't
need to restrict herself to the bland, safe, and stylistically blessed.
(Although she might choose to, to spend her time in ways other
than wrestling with cranky apps.)
OTOH, I do have other relatives with less clue (or less belief that
they could acquire clue), that would probably be best off with either
pen and paper, or with something in a nice sandbox.
All I care is that X11 apps and Java keep working. Vuze is written
in Java, and I like it fine, it's more informative and controllable than
anything prettier/native would likely be, and the interface, while
not 100% Apple-ish, is close enough not to be too much of a pain.
For X11 apps, another example: GIMP vs Seashore. Both have
pretty much the same guts, but Seashore has a native interface.
OTOH, it was simplified enough that it doesn't provide access
to a lot of the functionality of GIMP. My mind doesn't seem to
work in a way that makes image editing easy for me, regardless
of which tool I use. So for me, an easier tool with less features
doesn't have much point to it, because either one will be a pain
for me to use.
In either case, while I like the consistent interface of Apple's Mac
apps (and those of many 3rd party developers that choose to
do a good job of following the interface guidelines), I've used so much
different stuff over the years that I'll take functional over pretty any
time, if I can't have both at a price I'm willing to pay. Mainly,
I want all sorts of apps (both ".app" apps and otherwise) to
just run, preferably _without_ all sorts of prerequisites to download
and update separately first.
Java apps, while not able to be as lean as native code, don't
_need_ to be huge, slow pigs; that's the developer's fault, not
Java's. And Java doesn't crash all the time, like Flash does.
(not sure about power efficiency on a mobile device, but since a lot
of phones have long supported Java, it can't be that bad)
On balance, I suspect this is about getting rid of cross-platform
development environments, to funnel more traffic to (and money
from) the Mac App Store. Like most such approaches, I think it's
short-sighted, since building the customer base ensures the future,
while milking the customer for every possible penny today is likely
to reduce the customer base.