Your here objections to Didacgomez's post are quite solid for a westerner. Most western people, at least, would be well described by this, i think.In your view, it is as if it was his fault for not having the power to change the very situation he came from, that is simply not true. You can't expect to blame him for having a much better life than anyone around him even imagined for him.
It is in everyone's responsibility to make the most of the opportunities of each own life, it can not be pretended that if some others did better, they magically owe it to someone else who did nothing for them in the first place.
In his life experience, he did not spend his time blaming others or waiting for other people to take care of his own problems, so he's not the hangman of anyone, just the saviour of his own life. That's pretty much admirable at least.
Thing is, Takemura's not one. From what we learn in game, the opportunity to become Saburo's bodyguard was the highest honor for Takemura, taken with great deal of self-sacrifice and with many years of extreme effort. In his mind, it was not "an opportunity". The idea of "maybe i should decline this job" - never ever crossed his mind. The moment Saburo chose Takemura (it was outta ~hundred candidates if memory serves?), it was decided. So not an opportunity - instead, a duty. Very hard one, too.
I think it's fair to even consider Takemura's lost "his life" the moment Saburo chose him. From that moment onwards, Takemura's life belonged not to Takemura. It wasn't a "job" he took - rather, it was a sacrifice he made. His personal goals, ambitions, desires - everything of the sort was put away, and all his time was instead devoted to make sure Saburo is safe.
This all is from Takemura's own words, mainly "sidelines" (blue) and some few big "optional" sections of dialog with him which V can get. At least, this is the impression i got about his person.