A bot on a channel doesn't make you successful in all of a sudden, but it does help with the process of growing your channel. You have a point system? Users will stick around, even if at first the awarded points are useless, just to boast later that they were there 'from the start'. Random users will start coming by too and hanging around for those points and whatever else. Twitch has a feature called 'hosting' which allows you to host another channel on your own, for your viewers. You can offer this service to friend streamers, and in exchange get the same service offered to you (I do that all the time, and it worked nice so far). Having a bot with interesting commands/systems in place can and will determine visitors and users to hang around even when you don't stream for the sheer amusement of chat and mentioned commands.
But yea, I don't agree on the mentality of some (don't think majority) new streamers that a bot will make them famous. I for one saw it in someone's small stream and, noticing the point system, decided I want one too. Then other commands came in... and it just became fun to program the bot to do stuff I want it to.