Absolutely true (though I owe the original insight to another Joel -- +Joel Spolsky
). This helps explain low pay in game jobs, difficulty turning a profit selling compilers, and so forth.
If everyone wants to do it, then "it" is not going to be paid well. If you want to do it anyway, find something either sticky (e.g., effective branding, per the Dolby and Panavision examples in the article), or shitty (e.g., boring-but-useful integrations with other products).