because it's a competitive outlet where they can test their skill against other people
That's inherent to PvP. Players can exercise choice in the characters and weaponry they use and still play on a level field so long as the different options are fairly well-balanced. And whether you and your friends recognize it or not, this customization and specialization is what keeps people playing. It's why the most successful MOBAs have hero pools of 100+, why shooters also are starting to use hero systems rather than broad classes, why Dota 2 switched recently from attribute skilling to a HotS-like talent tree, why every new PvP game has players further tailor their characters with items or cards or customs loadouts. Players invested in a game or game mode find their niches or preferred styles of play and relish the opportunity to settle into them. Simplified games most benefit newer players, who might otherwise feel overwhelmed.
I address your "elaboration" right after that in my post. Potatoes are not PvE specific and are in fact required for Conclave, so that does in fact affect your point.
My main point was that they'd focus more on conclave-specific rewards if they were just looking to reward conclave players.
Everything used in Conclave other than the mods is also useable in PvE content so arbitrarily defining things as Conclave "specific" is pointless in the first place if you're just referring to things that are directly useable and affect gameplay in the game mode. It is however, a Conclave exclusive reward and it should stay that way.
The mods are a big deal, so you can't just gloss over them. By "conclave-specific" I mean things that can only be used in the conclave, which isn't arbitrary at all. That only conclave mods currently meet this definition doesn't mean they're the only possibility. On a different note, though, I don't think DE would get as much backlash if it had conclave reward the occasional conclave-branded weapon skin to be used in both PvP and PvE, particularly if DE made clear that it's not a one-time thing. I think people are mostly upset that they can't get any sort of Oro statue without doing conclave, and that despite its use as a conclave symbol it seems a more general object that could have roots in lore. And the people who don't like "one chance" events are also complaining and getting mixed in with those who just hate PvP.
Considering the fact that people around here frequently wave around the thousands of hours they've put into this game as a badge of honor, it's really not.
By now a player can have racked up 1500 hours just playing an hour a day. They can have vastly different life situations than they did when they first started playing. You can't even say that the people who have played thousands of hours are generally the same people complaining about this event. 3 hours is a good chunk of time, period.
No, they're just saying they should get it for doing something they want to do. The statue is not for them. It's a reward for people who like Conclave or were willing to try out and grind the new game mode. It's a Conclave exclusive reward.
They like the reward. They like PvE Warframe. They'd prefer to be able to obtain the reward in PvE Warframe. This preference is possibly affecting their enjoyment of the game and their likelihood to spend money on it. It makes sense they share it.
The statue is not for them.
No, as DE depends on them for their livelihood, everything in the game is for them. What's not for you is these players' posts.