In a way... that’s kind of what the upcoming updates will do. With the proposed revamped system, new users will start with 0 Steem Power, not the 15 SP delegation they receive now. If someone sits at the initial 25 rep, sure they can throw flags all they want... but with 0 weight and no effect. Attaining a 30 Rep is rather easy, I’d guess the positive votes needed to hit 30 only amount to about 2 SP of value at most. Essentially a 30 rep account will have unlocked the ability to throw 2 SP weight flags. The main abuse ongoing here is the use of unearned, delegated stake for these trolling purposes. Steemit Inc. does already allow for reporting of these bad actors to have their delegation removed however.

So essentially, you’ll be unlocking flagging power as you raise in reputation (which can only occur with positive earnings.)

The other part is simply education of new users. Once users realize the flags they are receiving have no impact on their post or earnings, and are completely random & automated by asshats, I’d hope they can easily look past them. If not, an open social media system will never be the right fit for them.