There will be (and most likely have been) plenty of shows you were not trying to play, either because you weren't too excited about the venue, or about the band/artist that asked you.
THAT'S COMPLETELY NORMAL. *Not every opportunity is the right one.* You DO NOT by ANY MEANS have to play every show you're asked to. Value your time - because if it's not the right show to play, you can invest that time and energy elsewhere that could very well help you down the road.
Some things that didn't quite make the vid because Instagram only gives me a minute of time:
#1 - When you decline a show, MAKE SURE to give them some options around your area. Other bands, artists, or events that may perhaps be a good fit for them. You should absolutely respond (within reason - some people are just creepy as hell. So I mean, always exceptions.) Reputation goes a long way in this industry, and if you don't respond - it gives one excuse for someone to gossip about you.
#2 - Why should you respond? Even if they aren't the right fit. Well, let's say this band is touring in from Detroit. Next time you want to tour through Detroit, you'll have a contact. Even if they aren't the right fit, they may know someone. And since you respectfully declined them, they should have no beef with you at all. Hell, you may even have a place to crash!