If so then why shouldn't upvotes? All votes are about adjusting rewards and that can be downwards. This question has been asked many times, but I still don't see it as necessary and people could lie. If people think you are abusing the system then they ought to say why, but that is their choice. Downvotes are actually a tiny minority of votes here, but can be an issue if you get targeted. All part of the anarchy of Hive I'm afraid.
I have had thousands of downvotes myself, but most are insignificant.
Downvotes without that weight of reputation is absolutely fine, democratic even. The downvoting with weight, and downvoting en block is a concern for sure based on the comments I have read here. The knowledge that it can happen creates an unnecessary block for any one who want to contribute but is unsure. Not everyone will be lucky like me to get good mentors :)
Those with the power need to be careful as other will notice their actions. I do downvote some blatant abuse. When it's down to personal disagreements I tend not to get involved.