This is why I think every company should hire B and even a few C+ level talent. Someone has to do the boring details.
I think this is just a common Google problem; when you hire A+
level talent they don't want to spend their time adjusting css
for every platform.
In this case, Google plus as a blog, obviously all the platforms are targets. So the CSS should be adjusted for all the platforms, and that must be part of the specs. If you have A+ talent executing, either it will be done, or they haven't implemented that yet according to their priorities, or there is something more unknown to us.
Anyway, building a G+ app doesn't exactly require an extra 30 points of IQ and 5 years of school than making a web page display readable.
Maybe they should start using CSS brain teasers in their interviews, then.