Is rushing the game a cause for boredom? your thoughts

[Zojha]

Being filled with content and being filled with content that people want to participate in are two different things.

^This.

If you only want "Content"...there's the entire gold saucer from Triple Triad card collecting to chocobo breeding coupled with LoV PvP. Two sightseeing logs, Crafting and Gathering plus oodles of sidequests. FATEs are everywhere, hunts are a thing, as is leveling your chocobo. And we haven't even touched the MSQ, regular PvP, dungeons or raids yet.

The more content you enjoy, the more the game offers to you and the less likely you are to get burned out or bored. You can achieve the same effect by playing multiple games at the same time - by spreading yourself thinner, you not only spend less time in any given game (extending content lifespan), but also have a higher diversity, so the gameplay itself becomes less repetitive.

That said, "rushing" over parts you don't enjoy to get to the ones you do does no harm, quite the opposite - rushing over parts you do enjoy out of social pressure however is bad.