is using a tube amp every day bad?

It's actually quite the opposite, anecdotal evidence has shown that the more you play the happier you are. 

Enjoy the music and play it all day Tube or SS. 
All is good!

Let me check the bible and other holy books that provide direction to peoples about good and bad....hold on......................................................................................................................................................................nope you are good to go! Nothing in there about too much tubes. Have at it and enjoy. Life is too short.  Just keep a few spare tubes around maybe if/when needed.

@mapman thank the heavens

If its an older amp just make sure the filter capacitors in the power supply have been sorted out. If they are failing they can take the power transformer with them and that's not pretty.

I wouldn't worry as much about the tubes!