My question is why you would want them to make a trial that is a huge buff to a weapon that you would never complete?

The reasoning is simple. Some people want rewards in a reasonable time frame. Some people want a feel of exclusivity. These trials kinda cater to both. Sure they don't get to feel superior because they do some insane thing that other people can't but they do get to freaking glow. It's just a trophy. That's all it should be. It's there to keep people who need proof of how hardcore they are happy without alienating the vast majority of people who just want their weapon.

Edit: I've already seen people excited about the trial. Those people as I said are clearly insane but that's what they wanted and they got it and they are happy.