Thought I would share my viewpoint on how the money works in GTA V since I don't see a lot of positive thought going for it.
To me the idea that I probably won't own every business/item/whatever makes the game more interesting. I think there are enough petty cash opportunities to have a good time (robbing weed farms, doing Maude's missions etc) that are actually quite fun to do when you compare it to say the PS2's arcade like taxi missions. I tend to appreciate and enjoy new upgrades/weapons and ammo for my shootouts when I know the money is scarce.
As for the bigger properties, I think it sorta encourages multiple playthroughs that give you a different pace of the game, a different experience. I think if you play the Bawsaq market well and couple it with online playtime to stall the game at slow points in the story, you can make quite an experience out of the whole package. Once you start using all 4 characters in this way, I think it works pretty damn well.
Just my thoughts.