What of the developer who works on something ambitious that ultimately flops and becomes a total write-off for the company or client? What of the developer who coasted along doing nothing on a team of people who built some billion dollar product? What of the developer who can't really itemize their contribution in dollar amounts because they don't have the foggiest idea how much in dollar amounts they contributed, apart from how much they charged for their time?
Failure on a project is not a communicable disease that spreads to other projects through developers; success is likewise. Failure is so common that a developer without decades of work experience runs a non-negligible risk of not having a big success. And having a big success does not predict with a high degree of certainty future successes.
To add to the trickiness of this problem, we can't just tell people "sniff out projects that smell of failure, and avoid." How would they know? Developers are not clairvoyant, so the solution to this is to use heuristics. Some of these heuristics are unique to one individual who got burned in some particular way. Some are as ubiquious as development best practices. Either way, they can be wrong for a particular context, or sometimes wrong in general but kept in peoples' minds by inertia and repetition.
This is a harder problem than just quoting dollar amounts, and assuming that zero net dollars means zero talent. I can't help but think that when someone can put on their resume "Built a site that made $x million dollars," it may be as much a reflection on their luck of being at the right place at the right time as it is on their ability to execute after finding themselves there.