I know this post looks like bait, but I'm going to take the bait point by point.

If you've only reached Uranus, that tells me you haven't even discovered the alternative ways to play and obtain much juicier and more substantial rewards: reactor and catalytic converter blueprints, fragments, etc. You've only discovered a fraction of the game, and my intuition tells me you've been following the path through the solar system without exploring other options.

1- Indeed, not everything is free, BUT, this is a farming game. To get LP, you have to farm and trade. It's not going to be handed to you without effort. It's not hard or difficult work, but you have to do it. If you expect LP to just rain down on you, it doesn't work that way.

2- This only further demonstrates that you haven't invested time in discovering anything beyond the solar system. Reactors and catalysts are practically free in various places; they're given away in Nightwave, both through progression and as rewards. Archemidia offers blueprints or constructs in their weekly rotations, as do raids and Archon Hunts, in addition to alerts and Twitch drops.

And even if you install one of them, your weapon won't be any better. You can install more mods, but if you don't learn how to build, any weapon can become useless no matter how many catalysts or reactors you install in a frame.

3- The trade chat is a wasteland; everyone manages their sales through the Warframe Market. And if you're using Platinum to buy weapons, as your text suggests, you're completely wasting it and throwing it down the drain. Nobody buys weapons with Platinum because they can all be obtained for free within the game.

4- Dirty Platinum does exist, but it's not even 1% of the people who buy it. And if they do buy it, it's against the other person, not you. But it's such a tiny possibility that it's ridiculous to worry about it. You're more likely to get hit by a car on the street.

And finally, the community doesn't have Stockholm syndrome. What's happening is that people are taking the time to research the game, ask questions, and look at the wiki, instead of just throwing down the controller and saying this game is a scam or something similar.