The argument really seems to be "I hate reaper therefore nobody should play the game". How folks apply their time, money etc is their business. Personally I think reaper is a brilliant addon to the game without dramatically re-engineering it. It also encourages players to build groups (especially if you're in a guild) so really the folks complaining are merely exposing their own weaknesses either as technical players or group players
You are 1/2 right. How people spend their time and money is their own business. Reaper "could have" been a brilliant addon to the game that gave people the "challenge mode" they were looking for without re-engineering it. There is a glaring issue with this argument, however.
You see, reaper was not introduced purely as a challenge mode. There are rewards that are exclusive to Reaper mode, rewards you gain from playing Reaper that extend into the normal version of the game in fact.
You get more xp/quest in Reaper.
You get stat bonuses from Reaper tree cores outside of Reaper.
You get the stat boost from Reaper hats outside of Reaper.
You get increased drop chances from Reaper Chests.
More and more Reaper lfm's have become the norm.
Reaper raid groups are becoming more and more common.
You see, the challenge mode some players wanted was effectively shoved down the throats of everyone else. Want to stay relevant in the game, you better be running Reaper. During the discussion concerning Reaper before it went live I distinctly remember people saying there should be no reward structure for playing Reaper, it should be strictly a challenge mode. One of the primary counterarguments to this was "no one would play it if there were no sufficient rewards". This implies that the mode would fail on its own merits, a reward structure is needed to bribe people into participating. Because of this people who would normally have no interest in it were forced to deal with it else they would eventually be obsolete.
You are making a huge assumption that the people complaining about Reaper "suck at the game". I can not speak for others, but I can solo on R7 comfortably, I am not trying to brag about being "Uber". I'm not doing R10 solos, but I think being able to navigate all of the various forms of reapers and survive the massive penalties at R7 demonstrates a fair level of competence. I could make the counter-argument that people who can only complete high-reaper in groups are relying on other people as a crutch to carry them.
I mean, if we aren't soloing R10 we obviously are not very good at the game right? The common argument for adding on to the reaper system is that it has become too easy right? So since you can so casually insult such a large portion of the player base you can demonstrate your superior skills by providing us with some of your R10 solo videos right?