As a person who has worked in the service industry for a few years, I am still continuously shocked the way bartenders and waitstaff are being treated to this day. They are not superheroes who can just magically make everything happen but they do their best to make sure your experience is as perfect as it can be. Your bartender will make your experience worth the over priced drinks if you let them, and it's time to step up and just be respectful. They are humans too, so be kind and please be patient.
At a bar they may not get to you right away if it is busy. That is just how it goes. You have to be patient with them, and they will make sure you are served. Also, it helps to tip them as well. Everyone has off days and this maybe one of your bartenders off days where nothing is going right and you can tell that they are frustrated. They have to pay bills too and just giving them an extra tip might be the boost they need to feel a little better.
Also, please use your manners. You can see someone's true self when they talk to a bartender or anyone in the service industry. Those are their true colors and often times people will not even say thank you or engage in conversation just to belittle them. Like I said before they are people, they have feelings, and they have off days just like you. Don't blame them if your food or drink is late because they have other customers they already have to memorize and make sure their food is out too. It is a never ending game of catching up and making sure everything is out, as well as making sure everyone has what they need. The game is never over until the end of their shift.
They have to deal with all types of customers which include the worst ones that can make them wish they were gone or those that they would love to talk to for hours if they could. They have to give their service to everyone and treat them all with great service regardless if they are being picky, loud, cursing or just obnoxious. I always cut my bartender a little slack because I know the position and I know how it is to serve those that may not be the nicest of people but you have to do it and you have to put on that fake smile.
Finally, please tip your bartender. I know the tab will be high if you did order enough drinks but you received the service and you should honor that by making sure they receive a tip. It's their job and they will provide the best service they can to you. They are there to make sure your night goes well and that they can contribute to the fun.