Yup as far as I am aware all the main protagonists, or at least the ones that had any level of dialogue or character within the games have been measured individuals who do what they do because they have to. Yes alot of the missions require a level of madness and explosive stupidity but all the characters up to Trevor come across as only doing the things they do because the mission asks you to, if they had the chance they would do things different more measured and more controlled, Trevor is the first main protagonist in a GTA game that actually matches the mental picture of someone who would do the things you end up doing in GTA.I will defend Trevor, though, as he's the character that GTA has needed for a while. Most protagonists tended to be within the same contradictory mold: a stable person who tries as much as possible to not cause too much trouble in the story, but is meant to be completely the opposite in the single player.
The thing is a lot of people would look at Trevor and see a one dimensional nut job who loves blowing stuff up, killing stuff and drugs but when you see how he treats Madrizzo's wife you see that he isn't just a one dimensional character and while you can say the humour is often childish and forced and doesn't really come across as subtle or even clever the fact is Trevor's softer side doesn't feel forced, it doesn't feel shoe horned in to the game it doesn't even seem to go against the character that is being shown to us and what ever you want to say about the writing or the character it's not easy to make a socio-pathic, drug fuelled nut job come across as someone who might actually care.
I am a tad confused though why the review of a game that has been out for nearly three years and has had no new story content in the mean time?
Actually it didn't try it was and still is a part time MMO; character development stats that can be maxed out within a week of playing the game, an economy that turns out to be utter fluff once you work out that it actually doesn't have an sort of in game economy, level limited unlocks that run out once you get to level 120 (I think that's the last unlock the Rocket Launcher.)GTA Online tried to be a part-time MMO, but good MMO's can't be made in one's spare time.
The flaws with the on line are mostly of Rockstar's own making, in the early days I spent two or so weeks working missions to gain enough money to buy a Buzzard (you also needed to be a level 50 to use it.) I finally managed to get hold of one, used to spend time flying round hunting bounties. The aircraft actually took some skill to fly and it was by no means an overpowered vehicle giving the player an insta kill ride, I ended up actually getting pretty good with it. Rockstar then decided to add a homing missile, a missile that required no level to buy and cost 10,000 GTA$ a pop. Suddenly that Buzzard that I had worked so hard to earn, had worked so hard to gain the skills to fly and get kills with could be brought down by any level 1 noob using zero skill.
A lot of GTA online is like this, Rockstar add something, they then spend four updates trying to balance it before just giving up so they can add the next big thing that will generate Shark Card revenue. They never did balance the homing missile (e.g increase the cost or level to buy, ironically the bog standard unguided RPG still requires you be a level 120 to buy)
The Tank, people complained about it so they reduced it's armour, they then added the Insurgent which can take more damage than a tank, yeah an APC is tougher than a fucking Tank and the game is utterly littered with examples of poor planning, poor optimisation of stats and equipment, poor balancing, poor gameplay inclusion, it's all about cramming as much crap as they can to generate as much cash as they can and you know what I still fucking love GTA online, I still play it I have a level 450 and have literally nothing left to unlock but you get three or four mates in a session get some missions or hiests rolling and it is an utter blast, nothing beats it.
Like all the best things in life, it is flawed, badly flawed but on the best days you see past the flaws and see only the fun and every update is just another chance to find out what Rockstar has broken or nerfed by including that next big money maker that the public are demanding.