Indeed, though the problem here of course is that FFXIV uses a sequential Multi-Roll system rather than a Combat Table. In this case, 20% parry means you parry 20% of the hits which arent Crits, Evades or Blocks. In WoW, if you had 50% block, 20% dodge and 30% parry you'd NEVER get hit by an regular attack as it would total to 100% and regular hits would be "pushed off the table".
If you had those stats here out of 100 attacks you'd Evade 20 as this is checked first, but then block 40 (50% of 80) and Parry 12 (30% of the remaining 40). 28% of hits would still get through due to the sequential roll system. If you could stack out a combat table as a paladin to completely negate regular hits then Parry might be seen as a stat as vital as Accuracy (cap to x amount) but as it stands it's minor RNG mitigation at best.
I'm mostly butthurt that the devs told us they'd fix parry to be a desirable stat in 3.0. What did they do? They made it a fixed 20% instead of the 2.0 scaling from strength, cutting its effective mitigation by about a third, along with reducing the amount you get per point.
TBH, I actually -like- having a high parry rate (not that you get much choice in gearing nowadays). it's fun to see bosses whack you and get that little -20% come up in the combat text. It makes you feel like the gear you're amassing is helping you be tougher (something the current Tank Meta doesnt encourage). It's not even that Parry Rating is "bad", so much that you're giving something more useful up.
If they arent going to buff the rating, I'd love to see them do something lke they did for Accuracy for Healers: ALL tank gear has Parry on it. Every piece, without exception... but as a third secondary in additoin to acc/sks/crit/det and not taking up any of the item's budget. That way your parry rating naturally increases with your item level in the same way Str/Vit/Defense does, and you gradually increase your mitigation, but it doesnt take away from the DPS boosting secondaries.