You will always be criticised by those who are doing significantly less than you. 

Sadly, there is currency in being a critic. 
In being focused on finding fault without value adding to outcomes; and its increasingly becoming a leadership default because its effective.

Humans have a negativity bias which is easy to tap into. 
Its called positive-negative asymmetry – negative influences more behaviours than positive does. 

Critics conveniently ignore what you HAVE done; and spend enormous energy finding the ONE thing they feel you have failed to do, and this becomes amplified over all of the contributions. 

Because sadly; negative works.

Importantly it also provides a distraction for those who are doing very little to make a difference. 

Criticism by itself usually speaks more to a critic's lack of track record rather than of those they are criticising, I find.