Dont know.. maybe the marketing of the game as an "OPEN WORLD RPG" ?
Are you like.. a new gamer or why are you not able to understand what an openworld rpg is?
I dunno, every open world game with a plot just has you do sidemissions while following a central plot.
Kassandra in Odyssey doesn't take up pottery and ignore the Order of the Ancients.
Edit:
I'm actually going to say that I agree the Corpo Life Path is poorly written, though. Corpos that get "exiled" from their home corporation do become the basis of a lot of Edgerunners. We also have a severe marketing issue as while the Cyberpunk 2020 is 100% clear that the purpose of the game is to become a Edgerunner (basically a mercenary for hire and/or adventurer--remember this game came out at a time when the only game in town was Dungeons and Dragons or Call of Cthullhu), that doesn't seem to be what people thought of this game. Plenty of people expected to work for Arasaka or Militech rather than be mercs like 100% of the characters created for the tabletop game that inspired this all.
Furthermore, the OP is correct that it seems like V could just go to Militech with all of their information. Which is a good reason why they absolutely wouldn't let him leave that bar alive under normal circumstances. They could have done this differently, though. A way that made things better.
Corpo: "We have shut down your cybernetics. You cannot move and fight until we remove the implant on you. We have furthermore hacked into your brain chip. All proprietary information about Arasaka is being deleted from your brain! Prepare for transport and execution."
*Jackie shoots all of them with the help of the Mox*
Jackie: Let's get you down to my friend, Victor. He'll get your cybernetics working again--or at least enough to walk.