I read it , and I think that the advantage it gives is fair due to the early game investment and efforts it requires.
And I repeat, the jungler is not immortal, so if the enemy team cannot contest a early baron (considering the extra damage the baron deals to the attackers so early in the game), I think the problem resides in how the early game was played , rather than the feral flare itself, and than any other strategies that would had capitalized in early game, would have made the game even MORE ONESIDED.
Let's say, you are against a Yi that didn't gank for 15 minutes and you are 2/7 total.
What would have happened if you were against Elise?
BTW: 2 people with lifesteal can alternatively tank the baron and taking him down early.
Lifesteal OP?