Along with EBITDA and other funky accounting measures, they likely are warning signs. i.e. presenting fluffed up numbers prominently is indicative of something.
Why do you believe it's impossible for a 'core accounting metric' to be funky?
Just because something is widely used doesn't mean it's guaranteed to be actually correct or reflect reality.
For example:
It never makes sense to exclude depreciation for anything physical without adding back on some cost of wear-and-tear, since everything physical suffers wear and tear. I've never seen this happen in reports with EBITDA figures, nor in this report.
i.e. They're effectively presenting 'profit' figures that exclude some amount of real, tangible, losses. So it's really only a pseudo-profit, which is why there's a separate 'Net Profit' figure in every SEC compliant report.
Things get funky when you start seeing "community adjusted EBITDA" and its cousins.