Redirects are okay (and encouraged!) when there are multiple names for one page (usually when the name changed at some point) or when they help searching via the search bar (Tinker's Construct -> Tinkers' Construct).
Abbreviations shouldn't be redirects, for reasons that have been listed above. We have the ModLink and ModNav templates for mod links and navboxes, which use a common list of acronyms and alternative names. Previously there were individual templates for those - for example the IC-nav template was the IndustrialCraft 2 navbox. A number of those acronyms were more obscure and confusing than that - guess what the Thaumcraft navbox was? TC-nav? Nope, that's TrainCraft. Tc-nav? Nope, that's Tinkers' Construct. Thaumcraft was under Th-nav.
The wiki started back in the old 1.4 days where you had like 30 mods in a pack, and FTB Ultimate was big. Back then the two-letter acronyms may have worked well, but nowadays we have 100-200 mods in one modpack, and there are a lot more mods in general. If we already have trouble choosing acronyms for mods alone, I don't think it would be a good idea to try to do that for other pages as well.