While editing a document, I noticed Microsoft Word flagged "In order to...." as bad grammar. The reason being that it is redundant because just saying "To" says the same thing. This seems like weird thing to flag as "In order to do X, we are doing Y" sounds more natural than "To do X, we are doing Y", because the "In order" part seems to emphasize that X is really what we care about. (This is just an example, I'm interested in understanding the grammar rule behind this flag)
I am also used to a culture of "redundancy is good", "redundancy reduces the chance of problems", "redundancy is more reliable"; So my understanding is that redundant language should be good, as it reduces the chance that the text (and its meaning) will get misread/misinterpreted. And while I see a lot of things online saying things like "redundancy is bad" and "avoid these redundant language", I don't see anything explaining why.
So why is redundancy bad? And why should I avoid it (aside from the fact that leaving colored squiggles under things would drive me crazy)? Or in other (redundant) words, if the sentence is still valid, why does this grammar rule exist?