The fact is, much of the US market has been falsely seduced by a national coffee chain that offers a dark and bitter roast. That's fine and serves the good guys well - as Rembrandt uses dark to accentuate the light, so the good roasters (and there are quite a few) use this dark background to reveal the truly great character that can only be brought out in a lighter roast.
It is a sin to roast a great coffee beyond its peak flavor. The darker you roast a coffee the more of its unique character you lose. The closer you get to charcoal, the more each coffee tastes the same. Don't misunderstand: French Roast is great coffee and we offer a very nice French Roast and we also offer a great Vienna Roast, but all the regional coffees offered here are roasted somewhere between city and full city roast, depending on which stage of roast brings out the best qualities of that particular coffee.
And, by the way, that national chain actually buys very good coffee (inside information) - it's what they do with those coffees that makes some of us wince (and rejoice).
While roasting coffee is an art and requires talent, skill, and an in-depth knowledge of coffee, some roasters do tend to take too much credit for the results. A roast is only as good as the bean going into the roaster and the care taken in brewing. It is the job of the roaster to take a great bean and bring out its best qualities, but before that step is taken by the roaster a thousand other steps have been taken to impart that great quality into the bean (and then the consumer has the final input in the brew.)
Having said that, there are quite a few industry tricks that adversely affect roast quality. The most common among them is decreasing the length of the roast to increase yield. Beans lose moisture while roasting. The more moisture lost, the lighter the bean, the lighter the bean, the more beans needed to fill the bag. (Is this where we get the term, "bean counter"?) So roasters, focused on the bottom line, cut their roast times down by raising the roasting temperature. Sounds like a great idea... to an accountant! Only one little downside, the bean isn't fully roasted! While the outside of the bean looks done, the inside will be under-roasted and the resulting coffee will have a "grassy" taste.
Another industry trick is to "water quench" the roast when it comes out of the roaster. Ostensibly to cool the beans, the underlying purpose sometimes is to elevate the moisture content of the beans and get a higher yield. But this has an adverse effect on the coffee's taste and shelf life and is completely unnecessary since the cooling fans do a great job bringing the bean temperature down rapidly enough.
Roasting exceptional coffee is a labor of love and does involve skills developed over years. In that way, it's a very rewarding vocation. You need to know your beans. Some beans like a lot of heat at the start of a roast, others prefer a surge in the middle. Some beans taste best at a medium roast, while others need to be roasted further to bring out other latent and intriguing characteristics. Not any bean makes a good espresso or French roast coffee. You need to know your beans.
So, a talented roaster is vital to a great coffee, but if you take a wonderful coffee, roast it to perfection and let it sit two months and then taste it against a middling coffee roasted any old way 48 hours ago, guess what? There's a really good chance that the "inferior" coffee roasted 2 days ago will taste better than the "superior" coffee roasted 2 months ago. Just check out the sell-by dates on those shelved bags of coffee. I've seen some very well known and "reputable" brands with sell-by dates 6 months to a year from now! Hogwash! Stale coffee by any old sell-date is still stale coffee.