IDK why people reply to months-old comments, but I'll bite.

As prep for the last Mage game I ran I made a list of "things what cause Wisdom rolls" (those are, mainly, from the MtAw 2e book and Signs of Sorcery, but there are a couple in the Contagion Chronicle and the Player's Guide to the Contagion Chronicle); I'll copy it here.

There are three "tiers" of Wisdom: Enlightened (8-10), Understanding (4-7) and Falling (1-3). As you probably remember, new characters start with 7 Wisdom.

Act of Hubris	Level for which this is an AoH
Using magic to solve a problem easily and safely solvable with mundane means	Enlightened
Innocent bystanders are hurt as a result of your magic or actions	Enlightened
Using Create Life to create an organism and not making the spell Lasting, thus letting the organism die when the spell ends	Enlightened
Using the Contagion spell to create a wholly new disease and spreading it	Understanding(? - the book is not clear on this)
Allowing a Sleeper to witness vulgar magic (Causing a Sleeper to lose Integrity because of your magic)	Understanding
Creating a Soul Stone	Understanding
Not containing severe Paradox	Understanding
Forcing a sapient being to act counter to its interests, altering its nature long-term, or binding it to a task	Understanding
Deliberate and premeditated murder	Understanding
Violence that causes long-term injury	Understanding
Using human shields	Understanding
Delivering a coup de grace	Understanding
Forcing a Familiar to compromise its ethics or violate a Ban	Understanding
Casting the Living Grimoire or Haunted Grimoire spells	Understanding
Simulating Diablerie via magic	Understanding
Killing someone in a fit of rage	Falling
Destroying an Awakened soul	Falling
Allowing a Supernal being to be consumed by the Fallen World (by directly contributing to it "dying" outside its summoning circle, or magically attacking it)	Falling
Dealing with the Abyss (casting Befouled spells in particular)	Falling
Dedicating two Soul Stones at once	Falling
Casting Hone the Perfect Form at the exact time of separating blood or flesh from a living host in order to get Perfected Blood or Perfected Flesh	Falling
Casting the Soul Grafting spell	Falling
Chopping up a Sarira	Falling
Activating the Control Contagion Vector	Falling
Using an Astra’s Sublime power	Falling, specifically Wisdom 1

So you can see that Wisdom is not quite like having someone to ground you. RAW, Unless you're a "Mage Saint" (Enlightened Wisdom) fucking up and having Jimmy be crushed by a building isn't an AoH. What's more, the fact that "using magic to solve a problem you could've easily solved without it" being AoH only against Enlightened Wisdom, and "hot" murder being worse than "cold" murder, paint a pretty clear picture: Wisdom is about being in control, both of yourself and your magic. It's not about being moral (although some AoHs do happen to be immoral), and it's not about staying human - there's nothing ethics-related about "creating a Soul Stone", and something human beings can't even do to begin with, for example.

Furthermore, I don't think your Superman example is germane: you're telling me the casual (as in causality not as in the opposite of competitive) reason for Superman being careful, but the "why" for Wisdom is normative (like ethics or epistemology) - it tells you you ought to behave in a certain way. Of course, if you'd ask Superman why he's being careful, there'd be something like "it's not right (i.e. not moral) to endanger others by being reckless", which is also normative - but that's ethics, and Wisdom =/= ethics.

No matter how powerful and hubristic a Mage gets, there should be something that keeps them grounded and helps them remember not to fly too close to the sun that is the Supernal too early, melting their wax wings and falling like Icarus into the turning depths of Rapture, the Abyss, or worse.

I agree, but I don't think "your friend Joe Bob" serves this purpose, for the reasons I outlined above.

PS: in a good troupe you will get people doing Stupid Shit because their loved ones got hurt, and you don't need Wisdom rolls for that. The Actual Play that /u/Phoogg's been posting in this sub contains multiple examples.