It is fascinating, is it not, that we rail against abuses of our language whilst many of us also contribute to its development and change.  I haz teh funzors play wiv mah langwage.  But I hate it when people are too idle to check whether they have spelled 'lose' correctly (they haven't, they have almost always put 'loose').  If they were doing that through a sense of fun, i wouldn't mind so much, but even following interrogation I find that the majority seem to think it is fine to spell 'lose' with an extra 'o', and don't quite understand that it is a different word.  To compound it, instead of 'lost' they then use 'loosed', and, I confess, a tiny part of me dies each time.

I suspect a large amount of the difference between the studies is because of different educational contexts between the countries, as you suggest.  I don't believe that we have been strict in our teaching or use of English in schools for about 30 years - I probably caught the tail end of it.  

But evolution of language is a marvellous thing - it adapts to our needs, and by using it adroitly we can establish different voices, and even erect barriers to slow the speed of transmission of ideas.  In an increasingly connected world, with concepts being sent globally at almost the speed of light, we have an intuitively odd situation.  We mainly want to be able to get, and disseminate, ideas quickly (unless we want to be able to profit from those ideas, when we keep quiet about them).  But the world is full of nay-sayers and those who are super-critical because it amuses them, rather than because of any actual, real, reason for criticism.

This can have the effect of dampening down new ideas - people hop onto the viral bandwagon and slap down new ideas just because they don't fit with their own personal experience, or because they enjoy exerting power over others.  Mob mentality often comes to the forefront, and things which should have had a decent hearing get lost in the melee.

By using language, such as jargon, we constrain the numbers of people able to understand what is being said.  Of course, by doing so we limit the audience to those who understand the lingo, and who, almost by definition, may have vested interests in arguing against our point of view - but at least they tend to be well informed, and because the lingo supports the community, they are bound by the norms of that culture.

One thing which may be troublesome, however, is that we are only just at the beginning of this many-to-many communication era.  I would not be surprised if the pace of change increases to the extent that communication becomes much harder, due to the creation and evolution of new dialects beyond our ability to keep up with them all.  Interesting times.