After the first time playing Thieve Guild, i realize a pattern here in Skyrim, all factions are not really in good shape and most of the factions are not really the real faction at all. It makes somewhat pointless
i. The Thieve Guild actually have been destroyed/cursed, should the player not joining it that guild will be out of business, and it is a Daedric quest in which makes the character have to sell his/her soul to a Daedra for the sake of the guild, why bother joining it? I mean, the character being recruited in an nearly destroyed guild, a nobody who suddenly getting involved in the guild politic and doing a sacrifice for the guild he/she just join in, and sacrifice for members he/she don't really know, sacrifice to rebuilt the really bad shape guild....it is not worth it. It is better just to leave the Thieve Guild to rot. They are not really thieves anyway but more to a mafia wannabes. Maven Black Briar doing better job without Daedric worship
ii. Dark Brotherhood isn't really Dark Brotherhood, it is just a band of assassin doing bounties. There is no Listener for a very long time, they doing their jobs killing peoples without honor, It is a fake Dark Brotherhood. Furthermore, they do take contract to kill the main character many times, the main character will never know who want to kill him/her and why, It is better just destroying them.
iii. The Blades are not really the Blades, it's only Esbern and Delphine.
iv. The Bard College isn't really make the character a bard, but a mercenary doing fetch quests
iv. The Companions are werewolves, they are not really good guys. The Silver Hand is the good guys hunting werewolves but they attacked everyone who pass by their base/fort like bandits, it is a contradiction. The Silver Hand hunting werewolves supposed to be protecting innocents from that abomination, but conversely The Companions is shown as good guys even though they are really bad and evil.
v. The Mage Guild is the only one that is okay, but the quest is bad. No one in Skyrim like the college, the Nords hate magic. The quest is actually "discover the weapon of mass destruction, then [censored] happen, clean up the [censored]". The guild didn't really helping the people with their magic, but actually making problem and fix the problem they cause. It is good if the quests making peoples trust the college and bring good name
vi. The Grey Beards are just bunch of guys who get boring in their live shouting at the sky and doing nothing. They protecting a dragon all these time.....
vii. Vigilant of Strendar don't give any meaning in the game
Joining factions don't really give satisfaction for me, because the factions are either nearly destroyed, fake one or in really bad shape. Unlike in Oblivion