I think over roasting allows companies to sell beans from different regions/sources as one batch. Can't tell the difference when everything has the same burnt consistency.
That's a pity, sacrificing quality and end user experience to squeeze another dollar out of the system. Reminds me of Cadbury chocolate, when I was a kid it was incredible - a real treat. Now it's waxy mush full of palm oil, all to squeeze more profits.
You can still find beans that are roasted properly from smaller roasters that use smaller batches. When I'm in doubt, I'll go for for light roast or a flavored medium roast. Light will have the most caffeine, but more acidic.