My take on it is that Americans were introduced to the Espresso bar by Starbucks but since then the quality of other coffee places has improved dramatically and now Starbucks is the last place you want to get coffee unless you are stuck at a hotel that has percolator coffee which has insufficient caffeine to get a buzz.

Part of the issue is that Starbucks buys in such large quantities that it can't possibly get the best beans.

My impression also are than both New York and San Francisco have worse coffee than average than the U.S. I think part of it is that Starbucks has saturated those markets so that stock market analysts will say, "Starbucks is doing great, there are five of them on the same block as my apartment and four on the same block as my office."

Most of those people never go to the 49 flyover states (including 0.5 of NY and CA each) so they think the rest of the country has as many Starbucks and the stock stays high.