What should be the primary goal of every drummer ?

Traditionally a drummer used to be a timekeeper, but not any more. Goals can vary from person to person. One should set his goals himself, where he sees himself after a certain period. No other person can set goals for you. But yes, I can help you to achieve your goals as a mentor, I've invested so much of my time, energy in it and gained experience of playing live shows & teaching (15 yrs now)  that I can help you to achieve your goals in lesser time.

Cheers! :)

The primary goal is to serve the song that you are playing. If you are playing solo, making the audience connect to you and your rhythm/pulse is what should be the priority. Simple is key. But making small but innovative fill-ins and changes/additions to the rhythms is what pro musicians enjoy on stage. :)

The drummer is the backbone for a band. The primary goal of a drummer is to maintain a constant tempo and dynamics and to support a singer, and he will be the master rhythm. Like a metronome to all the musicians who accompany the band, there are a lot of issues to discuss in different kinds of presentation. Still, the primary thing is to maintain a constant tempo and dynamics, which gives feeling to music for the one who plays.

The primary goal of every aspiring drummer or rhythmic instrument player is to understand what is his/her role in a musical ensemble.

For that, they should learn what rhythm means, what beat, time or pulse means and continue their education of applying rhythm in playing through telling, clapping, sticking techniques and also using legs as drum set players.