I'm not sure precisely what you mean by pretension - since affecting importance makes little sense in the context. I presume you're misusing the word to refer to 'tall poppy syndrome' or similarly to the Irish colloquialism 'notions'. The word reductive is perfectly common in English writing - according to the OED it dates to the 1500s. Perhaps it's new and frightening to you because you're level of literacy is not what it might be?
Perhaps we'd do better to cull the amount of words used? To reduce to available pool to the most efficient use of letters? Personally I think that would be double plus ungood, but perhaps I need to brush up on my 'normal people English'.
Look, sarcastic nose tweaking aside, a new word is a gift! When I come across one I add it to a list and count myself richer for having found a more nuanced understanding of how others view the world.
reductive is a form of simplification, but a specific form, one in which what is discussed has been reduced to fewer (probably just one) aspect, simplification is not necessary reductive as you can have multiple aspects maintained but each of those aspects made less complex.
