You don't have to have one. It is your right and decision to make this choice. To have a reconstruction like you said entails more surgery, and if you are happy with your body and don't want more surgery (now or ever) that is YOUR choice.
I say you go girl with any choice you make. And good on you for being comfortable with your new body. that may be the difference between you adn the other women you mentioned, they may never have got to the "I'm fine with my new body" stage.
I persoanlly had a reconstruction and I had mine at the time of my mastectomy and I personally am happy with that, but again this was MY choice, and this is YOUR chioce. WE are all different (isn't that WONDERFUL), so what is right for one woman (or even 100 other women) is not right for all women.