From what I can see, nobody wants any of us to know the answer to this question, regardless of which app is generating the message.
The answer is very very very simple, 99% of the apps you download take far more permissions than they require. There is absolutely no reason that the incredibly faulty tracfone app needs access to bluetooth, regardless of what anybody has to say about it. I, a very rare facebook user, recently logged in to flame the evils of SearchIncognito, a Firefox "privacy" app which invades your privacy to keep google from doing the same.
Many if not most app developers are doing far more than you might think with your phone, free apps are the worst, because they need to generate money somehow. This "denied to turn on" message seems to be unique to Android 4.4, kitkat, and it's not an error, it's a warning of invasive apps. You and I both denied the app to use bluetooth (because they have no need of it), and android will just continue to warn you of this, forever, and yes, it blocks the keyboard on the phone.
Change is coming, and we are the ones that are gonna have to force it. Privacy is over if we continue to use closed-source software. Androids claim to fame was the fact that they were an opensource, linux-based OS, until google bought it and ended that immediately. It's now relying on many closed source segments, so that yes, everybody that you ever download an app from can spy on you in a myriad of ways. Luckily you can actually control which of the permissions you blindly gave them access to when installing in Android 4.4 or later, but I do not yet know how to get those warnings to go away without digging into the android software development kit (SDK), so the smartest suggestion I have for you and all is remove any and all apps that cause these messages, because evil is being done at you. I found your question by searching high and low trying to determine why Facebook's SUPER invasive app is constantly trying to turn on my bluetooth as well.
The only safe thing to do is pull any all apps that cause these messages, complain to the developers, and require THEM to stop trying to access the services that create these error messages.
Welcome to the end of the world.