People are using stats not as a sole argument, but to back up their argument against other opinions that say thing like he's just a sideways or backwards passer or he just sits in between the two centre backs that dont have any stats for their opinion.
I fully appreciate stats can be skewed, but I'd rather have stats to help back up an opinion I see visually than no stats at all to back up what I saying.
I agree with you on this point, but there are many stats that back up the fact that Rice isn't very progressive. Below are all the deeper midfielders from the top 8 compared with Rice. Non-cross xT (expected threat - the ability to pass or carry the ball from a less dangerous part of the pitch to a more dangerous one) and progression received are probably the two most important. Rice looks decent on progression from passing, but his non-cross expected threat is low because he and West Ham go long a lot. That bumps up the progression numbers without being particularly indicative of his ability in a side that wants to retain possession, where long balls aren't helpful in a player's ability to be involved in the first and second phase of possession.
You can make the argument that West Ham weren't a very progressive side last season which skews his data and that would be entirely valid. Personally, I'm of the mind that players rarely change styles with a move, especially if one excludes players making adjustments to account for their declining physical ability.
Edit: Expected threat penalises a player for playing the ball towards less dangerous parts of the pitch (i.e. backwards). Rice being relatively good at progressive passing and carrying but poor for expected threat would imply he plays backwards a lot, or he does those actions from very, very deep.
Edit 2: Added Caicedo and MacAllister.
Edit 3: He's the lowest for progression received, implying he starts the first phase often, rather than being the recipient, or doesn't play in a system that uses the midfield for progression. In either case, he's a bad fit for what Arsenal are trying to do - build-up narrow through the middle of the pitch.