@humanearl sir...
Again....smart ideas about steemit....
I also noted most of the content on Dtube and steemit are self-referential. People are making lots of videos about steemit and Dtube. The platforms also tend to focus on cryptocurrency and cryptocurrency projects. I don't think this type of content will appeal to mass audiences. People will want to watch videos on things they like. To be fair there is some original content on Dtube though. There is also nothing wrong with being excited about a platform in the beginning either. Just as long eventually people do start to post original content that everybody loves.
Steemit also has a unique problem with certain users. Some people are worried that users with the most Steem Power are getting the most STEEM and using their power to prevent others from doing so. These users are called Whales. Keep in mind that users with lots of Steem Power or Whales make a much higher contribution when they vote on content versus smaller users. Some small users or minnows feel like they don't get any contribution rewards or very little rewards.
It is far too early to know if steemit, Dtube and, other steemit based platforms have a future. Steemit seems promising, but many startups do. Being promising does not prevent failure. The future of Dtube and steemit are very much connected. Dtube relies on steemit. If steemit grows and gain many users, Dtube will probably as well. DTube needs more content creators and viewers. If Dtube does gain a user base, it could possibly be a website that stands out from YouTube due to its policies. But I am not bold enough to make a claim like Dtube will surpass YouTube. It seems for now YouTube will remain king. I will be very curious to see how steemit and DTube are doing years later...
So is Dtube a good alternative to YouTube? It really depends on if users are willing to give the website a try. The developers of the website also have a lot of things to add and features to polish...
Good luck...
The crazy thing is that we are still in Beta with Steemit and Dtube. So there will most likely be massive improvements in the next couple of years.
Another thing you mentioned about the SP issues. Yes there are many right now trying to downvote people's content that they disagree with. This is a huge problem and it could severely effect the future of steemit and dtube.