A lot of people struggle to understand that a lot of the fun of warframe is in the progression. There really isn’t a lot to do that’s interesting when you get into the endgame, so paying to progress faster ultimately takes away some of that fun.

Now, there is plenty of fun to be had building and trying out new weapons, but that does get old without a goal to reach for while using them.

Also, very few people actually play the PVP mode. I’ve never touched it myself and I’m in the endgame.

So from an outsider who doesn’t understand this, they see that players can pay to progress faster and think it’s pay to win - because in most games it is.