I have only recently started upvoting my own posts. It was a difficult moral decision to make as I always wanted my work to be rewarded by others on the platform. Now with the big rise in voting bots i feel I have to compete for exposure in whatever way I can. 
Does my work bring value? I believe so, it will have long term value for whom ever stumbles accross it. It may not be as popular right now as some photos of a half naked girl or a post about Steemit reward pool rape but in the future long after the seven day payout someone will find it of value. 
After spending hours putting it together I want to reward myself for the work i put in albeit with my tiny vote. Otherwise whats the point in me keeping my Steempower stake.  I do wish the system was working better for content creators like myself but until the day that happens unfortunately Ill be selfvoting my posts. 
My cooments are to try and bring value to other people's work and it is for others to decide if that is so.  
I suppose what I'm trying to say is we all need to find our own ethical litmus test.