It's interesting that this is being upvoted, it is totally factually incorrect.
First off, they did not get banned because they "vote gamed/spammed reddit" and they did not get banned from reddit, they got banned from r/news. Why did they get banned from r/news?
The reason that was first given was vote gaming and spam, after a lot of comments asking for proof, none was given. When the moderator who banned the site was asked why he banned the site, he said "simply because it's the Kremlin."
RT posted a good summary of this whole thing: http://rt.com/news/rt-reddit-ban-kremlin-261/
Interestingly enough, the moderator who banned them "Bipolarbear0" has recently been receiving a lot of criticism for many things, among them is censorship of the many subreddits he moderates. This was recently brough up by Glenn Greenwald himself for the censorship of his article on jtrig.
Now in regards to whether RT has been spreading propoganda is factually false. RT is funded by RIA Novosti which is a Kremlin owned news organization, it owns many, many news organizations, one of which is RT. RT was described by Putin himself as created to spread an alternative perspective on the news. What does that mean?
It means that unlike most western news organizations, RT would not use a western bias, but instead have a Russian bias. The reason many people liked RT is that it brought more independent and centrist views on the news with regards to world news, but many disliked that it had an obviously pro russian bias in russian news. As a result RT had on many people who US news would never bring on, the prime example is Noam Chomsky who has been censored from US mainstream media for years.
I digress, the main point is that RT was formerly a very independent news source with regards to world news, while having a russian bias with regards to russian news. The reason people like RT is that it offers a different perspective to the american mainstream media in a way that allows us to be able to draw our own conclusions instead of just "lapping up" US propoganda (which by the way was legalized in last years NDAA https://en.wikipedia.org/wiki/National_Defense_Authorization...).
So maybe next time you analyze other news sources, opinions, and world views, you should account for cultural relativism. Because the only reason your comment is being upvoted is that it has a clear American bias.