I think it's not so much that the question really is "nuanced" - it more that by its very nature, ELL is likely to have a high percentage of users who are interested in knowing what's grammatically correct (whereas ELU users tend to be descriptive rather than prescriptive).
When it comes to the dafter prescriptions of Latin-versed Victorian grammarians (never split an infinitive, never end a sentence with a preposition, etc.) ordinary people feel quite comfortable shrugging off such misguided rules, because they're always hearing other people breaking them.
It just so happens this particular point is one where ordinary native speakers can't casually decide what's "right" on the basis of personal experience, because it only really concerns a meaningless quirk of orthography.
In the minds of native speakers unencumbered by artificial notions of correctness, used to is a set idiomatic phrase that doesn't "conjugate" like a normal verb - but because they'd pronounce use to exactly the same, they may feel uncertain when told that's how they have to write it in some contexts.
There are a number of what I consider misguided comments (and answers!) on the ELL page, but I don't think the average visitor seeking enlightenment will find it too difficult to understand the issues involved. If they want to endorse the prescriptive or descriptive position (knowing exactly why either may be decried by the other camp) they're free to do so. But as many have pointed out, it's easy to rephrase so you don't have to make a potentially contentious choice.
As regards the specific comment reproduced by OP here, I agree with @Alan that it's not very helpful. But it's no big deal - the net position is reasonably clear, and there are several links to related questions on ELU that should clear any remaining confusion.
TL;DR: There is no problem to be addressed as regards the specific question cited here. For the more general case, if you're comfortable using ELL and your question isn't manifestly Off Topic, it shouldn't really matter if it might also be acceptable on ELU (nobody's likely to suggest migrating it!).