What do the people who operate these bounties think of the newbie invasion?
The newbies are less problematic than the jr. members. Usually the minimum required rank (e.g. sig. campaign) is jr. member. Bounties often have Google forms, and this can get attacked/abused easily when applying. A recent case that I've reported to a moderator was ~50 jr. members applying within 30 minutes (all the classic spam accounts). Merit requirement needs to be added for this rank, and it should be a tad more than 1 merit.
I agree. I believe that most of newbies are only an alt account and spamming the forum to rank up to Jr member for signature bounties. It would be a nice idea if those bounties have minimum merit requirements to be eligible for participation. That way, they might try to ask their selves what are the best way to achieve merit.