It really depends on how it is handled.

In FFX, unlocking the monster arena bosses was probabley a bigger effort than fighting them. The monster arena itself was interesting but FFX wasn't just limited to that. It had blitzball, chocobo racing and numerous other bits. Overall, not half bad.

Crisis Core (which i'll just mention i love before i commence the bashing) had missions which were constant recycles of maps and monsters. 300 in total if i remember and just grew more tedious the more you conquered. A few of them had some dialogue or interesting enemies to fight but it wasn't nearly enough.

FFXIII marks were lazy. You knew where the cieth stones were (They glowed on the map) you were told where the mark was (with a little star on the map) and it was a simple case of "go here and defeat it" much like Crisis Core except it takes place for the most part over a single map.

FFXII was the game that did it right in my opinion. Seeing a bill posted for the hunting of a mark meant first having to find the petitioner. Finding the petitioner wasn't a difficult task, but talking to them makes the whole hunt more involving. The mark is being petitioned for a reason and you feel as if you are helping someone by vanquishing it. Finding the mark is the next bit, often you have to find clues as to where you'll find him or how to make it spawn, usually certain conditions are required. Next you have to fight it. Most of the initial marks aren't anything spectacular, but later you'll find many marks who are memorable, challenging and will test your ability for battle, Often giving you a sense of acomplishment for overcoming them. Finally you must head back to the petitioner to claim your reward. Watching your clan rank grow in the clan hall and joining other mark hunters adds to the experience. FFXII also had fishing, pirate olympics and tbh a great tonne of sidequests apart from mark hunting to take part in.

I agree that mark hunts are becoming a common thing in FF, but that's not always a bad thing, it depends on how it's handled. FFXIII is a linear game so even when you think you're being given sidequests to do, you'll see that it's still a case of "Walk here - fight this" and little else. In other words, not very involving and poorly implemented. Future FF's won't nessesarily follow FFXIII's formula and such marks would be handled differently also.