I can't tell if that last statement is a final hanging droplet of your diarrhetic outburst of sarcasm or if you're insinuating that there's no way to teach players through subtle visual cues. Please refer to Egoraptor's knob-gobbling video on Mega Man X's intro level for reference as to how these things used to be done quite successfully.
I wasn't being completely facetious when I said the problem is adults, though. Games like MMX existed in a time when video games were, rightly or wrongly, still marketed primarily to children - children who can be reasonably expected to just try things until something produces the result they expect. There's an unfortunate tendency for people, right around the age of 15-16 (when one first learns to operate a 3-ton speeding death machine), to adopt the idea that maybe they should stop fucking around with machines that they don't fully understand, no matter how innocuous they seem. So while someone who either is of learning age or was of learning age when they first started playing video games either knows fucking well or can fucking well figure out that, yeah, the usual standards apply in this game too, the mothers and other grown-ups that Nintendo is reaching out to will usually stand there looking dumbstruck and go "What do I do I don't know what to do tell me what to do" without even trying anything.
The only solutions here are to close off the gaming medium like we've closed off so many others, have some sort of system-level or game-level setting which assesses your skill level (which will still be set to "moron" on any store display), or just accept that modern video games actually make fewer assumptions about your intelligence than before and stop taking it personally.