No, I disagree with the absolute, here. Anyone can take offense -- I could take offense to this statement, claiming that you're now calling me an insensitive jerk who can't communicate. How a reader reads you is as important as what you say in communication. If the statement isn't outright jerky or dismissive, if the reader assumes it there's very little a different form of phrasing will accomplish -- they're disagreeing with the argument, not the phrasing. And, this is the point -- it seems the very suggestion, however phrased, is viewed negatively. That's not on the speaker.
This goes directly to the unspoken assumptions I stated. If you ask how to run Aliens in D&D as you put it here, it's perfectly normal to provide an answer that suggests trying something other than D&D. This is because the asker may not be aware of other options (this happens often), or may not be aware of specific issues in accommodating tropes and themes using D&D. No, what's missing here is the statement that the asker will no consider any other game other than D&D -- this is a hidden assumption. And, it's the assumption that's causing the issue, as the asker is feeling offended that people ignored the ask that they did not state, or has assumed that everyone else has the same base assumption that D&D is the one game acceptable. People are trying to help when they suggest other games -- if it bothers you that they do so, then this is your issue, not theirs.
The assumption of condescension or dismissiveness to an unspoken requirement of the ask is the fault of the speaker -- according to you.
Yes, I can absolutely be condescending and dismissive. I am not so when I suggest a different game may have more success for some things than D&D, though. If you read it that way, it's on you, because the advice is neither dismissive or condescending. The only way that is possible is if you have a massive emotional attachment to D&D being the one true game for you and cannot abide suggestions otherwise. Because, the only thing being suggested is that you can play a different game to get a different result. This isn't offensive in any way. Otherwise people would get upset at suggesting that Risk might give a better result to someone seeking a wargame than Monopoly.
I call BS. This is handwaving and saying that your claims must be taken as the only possibility because you've seen things. I have, personally, told people that they only know D&D and should try other games, but that's been in the context of discussing how other games work differently from D&D and being confronted by a poster that says they only play D&D and that D&D can easily do everything the other game does. However, in saying this, they're usually exposing a massive ignorance that's obvious to anyone that has played the other game. System matters, and can matter a great deal. Your arguments here are effectively that system doesn't matter, that you can just modify D&D to do the other things. However, all of your proposals in this thread are just a slightly different flavor of the core D&D tropes. Nothing at all wrong with this, but it exposes a flaw in your arguments. You further solidify this with your complaints about Monsterhearts, and the mechanic that can mean you find out your character is, in fact, turned on by the bad guy. That's the focus of Monsterhearts -- it isn't playing monsters, it's dealing with the confusion of puberty, high-school drama, and discovering sexuality while also being monsters. If you're complaining that the system does what's on the tin, because it's not what you expect (which is the D&Dism of absolute player control over PC feelings, except for magic, which is given a pass) then you've missed the point altogether. And, that's fine, you don't have to like other games, you can be very comfortable with D&Disms and want to stay there. That's 100% legit. Just, maybe, be clear about that and don't take offense if someone else dares start with a different position.