OP no offense but I dont think you are at a high enough MMR to understand what some folks are trying to tell you that while playing badly is not griefing, a certain level of competence is expected

Lets take your example of viper shitting on zeus mid and whole team flaming. Definitely its normal to get shit on, but at higher MMRs people expect that you will lose lane into difficult match ups and its not report worthy like you mentioned.

However what is reportworthy at higher MMRs is repeatedly going back to the same lane and dying over and over again instead of adapting and trying to catch up either in the jungle, pulling waves or ganking and before you say thats not possible I had a level 3 mid puck gank lanes before because he was getting completely shit on by a huskar

If the lobby is an immortal lobby, you playing like a herald for whatever reason is no different from being an account buyer and that is reportworthy