The answer to aspecs asking you to stop assuming [thing] about all aspecs is not to start assuming [opposite of thing] about all aspecs btw.
"Stop assuming all AlloAros have a lot of sex (or "are sluts")" does not mean "Start assuming no AlloAro has lots of sex" and also not "No AlloAro ever feels comfortable calling themselves a slut (or whore or w/e)" and vice-versa.
"Stop assuming all aros are loveless and non-partnering" does not mean "start assuming all aros do love ("in non-romantic ways") and are always partnering" and vice-versa.
"Stop assuming all aces are sex-repulsed" does not mean "start assuming all aces are sex-favourable", and vice-versa.
"Stop assuming all aplatonic people want to make friends" does not mean "start assuming no aplatonic people want to make friends" and vice-versa.
"Stop assuming all [aros or aces, mostly*] experience no [romantic or sexual, mostly*] attraction" does not mean "start assuming all [aros or aces] experience some form of [romantic or sexual attraction]" and vice-versa.
[Continue ad infinitum; these are just some examples and listing all things like that would be impossible.]
Just stop making assumptions about people based on one part of their identity. If they decide they want you to know, they'll tell you. If you want to know, you can ask, and maybe they'll give an answer (don't act like you're owed one, tho).
Accept that all people are different and even people under the same queer identity are going to have a vastly different experience; especially vast umbrellas like the aspec-identities. Instead of taking what one aspec person says about their identity as true for everyone under that same identity and then taking everything else as a "contradiction" to that label, or as something that needs another or a different label, simply accept that different people are going to have a different experience even if they use the same words to describe them.
It's really not that hard.
[*I think this may also apply to other aspec-identities (aplatonic, afamilial, atertriary, etc), right? I see these takes mostly inside of and directed at aro- and ace-spaces; but it also seems like it just applies across the board, non-aro and non-ace aspec-identities are just lesser known and thus not discussed as often.]