What? The joke saying about that is "those who can't teach, teach gym".

Never heard anyone say that about software engineering.

Among many teachers it is, "those who can't teach become education consultants/researchers."

The joke at my school was when the engineering students failed (mech, EE, civ) out, they went into business, when they failed out of business they went into software engineering.

And what happened when they failed out of "software engineering"?

Then they start a coding bootcamp.

Psychology.