This is not an issue of the party bonus not working. It is. People have demonstrated the math. SP earned is divided amongst the number of people in the party and the bonus is applied to the tune of 40% in a duo and likely scaling up from there as more people are added.
Even if this is not a bug, I don't think they intended it to work this way.
I see what they tried to do:
The issue is a direct result of SE's mind boggling decision to halve SP gain at rank 20.
And this is the key to it.
It is clear that ranks 1 through 20 act as the tutorial to the game. You get lots of skill up by yourself, and you don't need to rely on others to progress fast. While duoing and trioing may be better than fighting alone pre-20, it is not by any means necessary. It is extremely easy to make a comparison to XI and it's leveling curve (when do you start grouping, and why not earlier?).
Once you got higher level <in XI>, monsters of the same level would have much more HP and while they would still give the same amount of exp, it would be wiser to fight them in a group rather than alone. At some point it becomes nigh impossible to solo depending on your job.
XIV seems to use a different mechanic, but works in the same principle. When you get higher rank <in XIV> (20 in this case), the exp gained from monsters is halved. While I do not know whether there are other changes, by what I am hearing soloing is still quite possible at higher levels too, even better than grouping right now. Therefore, the HP of the monsters does not scale as much in proportion to the damage you deal as in XI.
Now, as far as the EXP system goes they seem to be quite similar right now. But the difference is, that while in XI the HP and scaling of monsters made soloing slower (or even impossible) than grouping, XIV halves the skill you gain to achieve similar results.
However, when in XI you could compensate to the scaling of mobs by having more members in your party and therefore gain as much, if not more exp than you did during your early soloing levels, in XIV right now such compensation doesn't seem to exist (as much, at least).
What this would mean in XIV terms, is that while fighting alone skill gain is halved, by having more members in your group the skill gain would slowly climb back up to what it was pre-rank 20, with the sweet spot being somewhere between 4 and 10 I guess.
Therefore, what is accomplished in XI by keeping the EXP same and increasing monster strength in relation to player, is accomplished in XIV by halving the exp yet giving a bonus to people fighting together which would create the same result, although not in a way that it hurts small groups or soloers as much as it did in XI.
Right now, though the system works the same way it does in XI, so what they need to do is change skill gain so it doesn't work like exp does, but rather make it so there is a set amount of skill gain you can get from a monster no matter how many party members you have, and with more party members you get a bonus to that set amount of skill.
It makes a lot of sense, and I think they are very close to a break-through here. Just not quite there yet.
And if we want to go beyond just fixing the system, they could award players who fight harder monsters (with a larger bonus/multiplier? Exp chains?). Lots of things they can do.
The problem I see here is that if you have only 30 minutes a day to play, you should be able to progress at a steady pace... while I thought guildleves would be the answer to this, I'm not so sure anymore. I think more needs to be done in that regard.
Guardian's Favor might be the answer here. It almost works like an EXP ring, and if they add something similar on top of GF I think they may be on to something. GF itself should probably, on top of boosting the skill gain, remove the -50% skill gain penalty above rank 20 (maybe even for a set amount of monsters outside the leve too). That way those with really no time to group at all will be able to progress but yet not make the system broken for other, more hardcore players.
Although still more problems arise from doing it that way. Edited, Nov 28th 2010 11:00am by Hyanmen