Agreed. To be clear I really like the idea of being rewarded for great RP. I like the concept of both the RPR system and the rewards system. It's nice to feel appreciated for the effort you put in, especially when that effort helps other players have a fun time. But I think Arelith has way too many players for any kind of 'hands-on' system to work. Even if every DM (who are unpaid volunteers) adhered without fault to a universally agreed-upon gold standard of RP (which doesn't exist), they would have to spend every waking minute monitoring the server to catch the nuances of everyone's roleplay. And our already-hardworking DMs are volunteers, so...nope.
The practical response is an automated system, and I think that system should be RNG. Measuring something qualitative like someone's roleplay is such a subjective matter, and people will game the system no matter how it's engineered. Let's be real: if the devs implemented a system where # of lines said contributed to the possibility of getting a major reward, do you really think that powergrinders wouldn't just stop circling the Orclands and instead sit inside in a corner, spamming chat boxes?
People will game the system. Every time, without fail. Some players are just like that. A different mechanical system won't change their behavior outside the game, it will just change it within Arelith.
You can't cheese RNG. It's not perfect, but it's fair.
On the matter of people powergrinding to churn out rewards: in principle, yes, that is not what the reward system is for and I would prefer they didn't do it.
In practice though these players don't affect my enjoyment of the game in any way since they're just running around doing PvE content. It's real easy to ignore them. I don't even know they're there most of the time. So I'm whatever about it, they can enjoy Arelith the way they want and I can enjoy it the way I want and we're not at odds with each other.