I went to one of the top coffee bars in NYC last week and the espresso I got was terrible. I'm no longer going to coffee bars because I can make better coffee at home.
Some simple logic here...
How did you determine that it was one of the "top coffee bars"? Logic would indicate that it might not be. The reality is that massive percentage of "top" coffee business (according to the interwebs) are total crap.
Every barista (no matter how good they are) pulls a crap shot now and then. Did you try a second shot? If not... logic would indicate you should have.
Just because you got a bad coffee (perhaps an anomaly or perhaps it's a bad coffee business) doesn't mean all coffee bars are bad. This isn't even a logic issue. It's a reason issue.
At the end of the day I can't help but wonder if you're going into coffee bars looking for an opportunity to validate your decision to spend thousands of dollars on coffee equipment for your home and/or get a nice ego stroke (rather than looking to learn about coffee).