Evolution in no way requires promotion in order to continue to exist.
In fact, if you were to wipe all knowledge of evolution off the face of the earth but leave us with all other knowledge of the other sciences I can guarentee that within a short period of time the theory of evolution would exist again exactly as it does today.
Evolution is not based on any 'faith' or 'brainwashing'. It just is. If you look at the evidence that exists in the world around us, it is the only scientific solution that fits it. There really are only two solutions to the whole evolution question.
Either A) The theory of evolution is correct to a very high degree of accuracy (there are no doubt a couple of niggly points that will be updated as new evidence arises).
Or B) The world was created with the intent that we believe that evolution occurred, because it is what the evidences tell us happens.
You use the 10 + 10 = 20 vs. 30 argument which is actually a great way of demonstrating that the theory of evolution is in fact correct. If you were to remove all knowledge of arithmatic from the world, we would quickly relearn that 1+1=2 and so on.
The exact same thing would occur with ToE. Failure to see this probably means that you don't have a very complete knowledge base concerning the dozens of disiplines that all point towards a ToE.
There are many topics here at EvC that go into the details of some of these evidenciary disiplines (is that even valid English?). They are definately worth a read.
As for why you see people promoting the ToE so much recently in the US is that it is being forced to defend itself from the ignorant public. Due to misinformation and lies a big chunk of the people in the US believe that there are other, just as valid, theories concerning the history of life on this planet.
This is just not true and there is a real battle trying to stave off ignorance.