One should think of the consequence of a rule in all cases, not just when the rule is applied to defend those that mock those you oppose.

Imagine the same standards being applied when someone is pretending to be you and maligning your name in public with foolish declarations.

Yes of course, I do. Yet, again, I cannot agree with your statement. First, I neither "oppose" Shell nor Google (actually I think Google is a pretty cool company). Still, I find the parody funny and it raises some interesting questions.

Next, in the examples not an individual is "impersonated" but a faceless, anonymous corporation. I would have way more problems with the parody if an individual (independent to if I like them or not) would be impersonated or ridiculed.

If somebody makes similar fun of my employer, I would not mind at all.