A negative answer is still an answer.
IIRC the problem with +16 was they went from available every month for 20 dia per jewel at 80 cap to only available in gashas at 82 cap then only available for 59 diamonds per jewels before they actually decided to put them permanently in the IS for their current price. Considering they made something that was easy to get and relatively cheap to super hard to get and super expensive was a good reason to complain about it.
As for the current +20s I do not see why we wouldn't complain about them, they are very hard to get, not really an option for f2p. Paying someone to play the wheel for you will only get you the jewels vs playing wheel for yourself gives you at least some items(useless most of the time) in that sense it's even worse then gasha's. Odds of getting +20 from wheel were not great with the old ones and simply terrible with the new one. Having a required item for endgame been this hard to get and this expensive is a very frustrating situation that doesn't benefit gf nor the players. RoM is already hard/expensive enough without that extra barrier.
why would making the jewels available more valuable then the current wheel? Isn't having players spend thousands of diamonds to get an item +20 optimal? the thing is would you rather have 10 players spend 8k diamonds on your wheel once a year or a hundred spending 2k everytime they make a new piece of gear? obviously these are fictional numbers but they carry the general idea. If the expense doesn't seem too high people will spend and they might end up spending more then they would have actually spend on the high price item. Also, more people will spend since it will be below the treshold they set themselves for spending. In short, lowering the overall price of +20s would make a larger appeal to a larger crowd and end up with higher sales overall. Also, the issue with the current situation is not only one of price, altough jewels are very expensive as it is, the fact that you cannot get them directly and need to get lucky for it is a strong deterent for many people who do not want to gamble. Were the jewels available for a similar price without the element of luck a lot of people might decide to bite the bullet and pay the price. I know quite a few people who currently stay away from the wheel, but wouldn't mind paying for the jewels were they ever sold normally outside of it.