Because
Location issues are brought up. The location issue for RIV is that its on the property of a torn down section of a Moderate resort (ie less prime real estate) and directly attached to very large moderate/value resorts.
The transportation is superior to those resorts and I do view it as better than those resorts for the location. So there is zero argument there.
Because people are not comparing RIV to AKV (everyone would hate it if it didn't have the savanna). They are also not comparing to OKW/SSR which for many is simply a resort you buy at when you want sleep around points and are rated likely in last place for WDW resorts.
Instead when talking about RIV (with its price point,
point charts, and MFs) you are comparing it to VGF, POLY, BCV, BWV.
AKV/OKW/SSR are all less expensive (before MFs), are cheaper resale, have lower point charts, and have lower MFs (although OKW is getting close and may pass it soon).
The location negative is that you are in a location that was undervalued by Disney because it was not park adjacent. It is not on the same level as those resorts you can walk from and does not have the views to make up for not being able to walk like VGF/POLY. They thus had to try and find a way to connect it to make it seem like its next to the park (same as the boat for WL/CCV/BRV).
Also for me the negative to being attached to CBR/AOA/POP is you are attached to 5200 rooms at resorts with lesser quality food and shopping options (IMO Deluxe vs Moderate vs Value). You also are a small resort (small footprint and less than 500 rooms) which when you see a influx of guests will be more noticed and possibly have an impact on your food locations.
All of that sums up the though its attached to a Moderate resort without multiple paragraphs discussed on various RIV threads.