You can make money if you curate intelligently. It takes had work though and I think that is the real problem.
Everyone can potentially make money posting but I understand that not everyone wants to put the time in that is required to do that. It is not something that everyone enjoys and some people aren't going to bother unless they make big rewards right away.
IMO that is just unrealistic and short sighted. You don't get something for nothing - or at least 99.99% of the time you don't.
The problem with trying to get rid of bots using captchas is that they can access the blockchain directly so it wouldn't work. We just have to accept the bots are there and will always be there.
Further if curation rewards are all you care about and you don't want to go to the trouble of curating new authors you can use the guidelines put forth by @laonie to configure your own voting bot.