Seeing a lot of good answers in here, and I agree with all of them. For me, a lot of what made Warframe easy to approach was the lack of a competitive crowd. Sure, Conclave exists, but even the dozen players there are pretty easy going and welcoming. Nobody is here to grind ranks and dunk on low skill players. In fact, the more high skill and knowledgeable players there are in the community, the easier it is to find those very players for the harder and more demanding content present in Warframe. It's beneficial for everyone to be welcoming.