This is a trick question. Aren't all bounties irrelevant? YES!
The rate at which bounties are ending up to be a complete waste of time is becoming alarming.
I'll quote you, the OP, to support the FACT that bounties are (as you say) a complete waste of time. They support one group...and it's not the participants, it's the "developers" trying to pitch their coin that bounty campaigns benefit, that's it! If an up and coming ICO has a great use case it doesn't need people on a forum or people with a twitter account to promote it.