If I've learned one thing in the 14 years I've been a full-time cartoonist, it's that you can not let anyone else define your professionalism. It has to be a personal ethos to which you adhere despite third party influence or acceptance. The old measuring sticks for professionalism are going away and now more than ever it's time for independent creatives to set the bar. Set it high.
Regard your good name as the richest jewel you can possibly be possessed of - for credit is like fire; when once you have kindled it you may easily preserve it, but if you once extinguish it, you will find it an arduous task to rekindle it again. The way to gain a good reputation is to endeavor to be what you desire to appear.
Good name in man and woman, dear my lord,
Is the immediate jewel of their souls:
Who steals my purse steals trash; 'tis something, nothing;
'Twas mine, 'tis his, and has been slave to thousands;
But he that filches from me my good name
Robs me of that which not enriches him
And makes me poor indeed.