Pretty sure this would just exaggerate the problem. Especially if endgame relic/mythic/etc currency got involved.

All linkshells would do would get a WAR to go into Abyssea and cleave for their alliance all day and night, and members would alternate taking turns. Meanwhile, everyone else in the group is racking up tons and tons of experience points which they would then turn around and spend on tons of currency.

Even if the currency gained was something slower than you would have by doing the event itself (someone mentioned 300 vs. 600 hours to get a relic), people would still opt for the easier method because it is easier. Plus with exping nowadays, you can just idle. Double the hours isn't going to matter if I can just idle in Abyssea and have it work for me.

Pretty sure it would just exaggerate the problem. Only way I could see it working really is if they gave you novelty items only, like nomad moogle cap or stuff like that.