Before you read the points here, keep in mind that some of the issues are not specific to your videos, but to tutorial videos in general.
One of the problem on the surface is, that nearly all your tutorials show code with mistakes. If you set out to make tutorials at least go over your code with the tutorials side by side and make sure it's not filled with mistakes or even better let it get reviewed by someone.
Just keep in mind that everyone watching your tutorials, will take on the same mistakes and we as community and helping hand, have to explain over and over and over again what they did wrong, or better said what you did wrong.
This leads to the next point. Videos are static content, meaning once you've uploaded a video it stays there until you delete it. Thus if you said something wrong, if you made a mistake or if SFML changes, your video won't adapt. People will watch and do the same mistakes or use the same outdated SFML "version" and again it will blow back on to the community who will have to explain many times over what went wrong.
If you barely understand a topic and you're trying to teach it to others, then you're doomed to either do things completely wrong or talk about things that aren't really true. Why do you think teachers go to universities or similar? Yes, they learn all the ins and outs about a certain subject, so if they stand in front of their pupils later, they actually know what they're talking about. A lot of information you think you know correctly is wrong and you're teaching these things to others, thus others learn wrong information and at one point will of course run into issues, issues that others have to solve/explain for you.
Don't underestimate the laziness of people. Sure, you say that your code style is not good or that one should really read the tutorials, but people are lazy. Those that are searching on YouTube for video tutorials on SFML are mostly exactly the ones that are there, because they don't want to read the tutorials. They want to be spoon fed with information and complete code examples. You can tell them over and over again to read the tutorials, but it won't help, they mostly don't want to read, they want to watch.
I haven't gone through your whole backlog of videos, but most of what you're teaching can be found in the tutorials, but without mistakes and in a generally accepted coding style, not to forget that the tutorials are always up to date with the latest stable version, as soon as there's a new stable version. From this perspective there are not many reasons to watch your videos.
To sum it up:We don't recommend your videos, because they contain mistakes, provide wrong information and teach bad coding habits. Instead we recommend reading the official tutorials, since they teach about the same thing, but have accurate information, do not have mistakes (or get corrected if any are found) and are always up to date.
I guess, I might come across quite harsh since I've only talked about what seems wrong. Your tutorials for sure can teach some things about SFML and I'd say if executed better, we wouldn't just say one shouldn't watch them. I guess binary1248 put it quite nicely in that regard.
My advice:Really learn whatever you want to teach. Don't just sit down, code and talk about things you've once heard or think how they might work. Just read actual books about the topics, but make sure they are good books!
If you show code, make sure it has been reviewed at best by two people with a high skill level in the used programming language/library.
And if you want to provide compressed but useful information in your videos, write scripts or rather notes for them. What do you want to teach? How do you want to highlight things? What do you want to explain in details? Which links to external resources do you want to provide? Etc. So you won't get derailed or lose track of what you actually wanted to teach.
If you want me to give specific examples on where your mistakes are, I'll try to find some time to write up a few things.