You can look at surplus as being a bonus sorta... if you do not play for awhile surplus goes down there for your sp goes up.

So technique if you put it in perspective. Rested Bonus is the Maximum obtainable SP. These are times of strait killing

WoW/Rift Rested bonus 200% (100% Possible Max XP gain) = last 20mins
FFXIV Surplus 0 100% sp (100% Possible Max Sp Gain)= last 3hrs

Time it takes in WoW/Rift to get to 50% sp: No Bonus XP 100% xp (50% Possible Max xp gain) = 20mins
Time it takes in FFXIV to get to 50% sp:FFXIV Surplus 5 50% SP (50% Possible Max Sp gain)= 1800 Mins

So if you look at the real Changes, FFXIV gives you around 1,780mins more Rested Bonus then most the mainstream mmos... just they do not call it "bonus".

It is the whole perspective things, both games are technically taking away 50% of the sp. One is perceived as a bonus, one as a penalty... but in reality they are both the same thing a 50% reduction in leveling over time.