I sympathize somewhat with your intention. The DotA community is definitely one of the most toxic, rude, immature, and downright racist communities I've ever experienced. Not that everyone, or even a majority of players have these qualities, but the prevalence of these traits is disproportionately high. However, I think the way you've attempted to tackle these problems is not productive for a couple of reasons.

I hope you don't take the following as a personal criticism, but instead as just a comment on how your dialog may be perceived by some others. The other commenters hit several of the major points:

As thewoodenaisle points out, these sorts of posts are emphatically not the sort of thing that people browsing the DotA subreddit are looking for.

As aidrocsid touches on a little bit, the tone with which you present these videos comes across as "standoffish, condescending, completely irrelevant, preachy, and annoying." It feels like you're targeting an attack against people of that community (and maybe you are), and in general people don't respond well to being attacked. Furthermore, such discussion is draped in a culture that many in the DotA community would find alien, and so it makes you like an outsider hurling criticism at the community.

Additionally, you respond to people's comments in a way that is standoffish, melodramatic, sarcastic, and condescending. Again, while these sorts of things may feel good, they're very likely to cause the listener to stop listening and attack back. Frankly, you sound like you've had some bad experiences with the game -- something which I can absolutely sympathize with -- and you've come to pass judgement on the people who might have contributed to those experiences.

I agree in general the community has issues, but I'm not sure what response you expected.