WRONG!!! People who insist that genetics are the end all, be all to fitness are simply ignorant and looking for a convenient excuse of not making any effort. To assume that all the pro bodybuilders and fitness enthusiasts succeed because they are genetically predisposed somehow gives the impression that they didn't work hard for it; that they simply became lean and ripped without any effort. Lucky devils no? However, that is a mistaken assumption. Pro athletes have suffer a lot of pains and strains to get to their peak physical conditions and they suffer for it. They may have the genetics for peak physical fitness but they still have to earn their prowess through blood, sweat, and tears.
The average layman uses genetics as an excuse of justifying his/her failure to achieve their fitness goals and to not eat healthy. The real reason for failure is bot just an improper diet or workout; it is the failure of their mind. Your body is a living and thinking machine; it responds not just to physical stimuli but also mental stimuli. If you admit defeat or justify failure, your mind set regresses and your body follows suit. That's why bodybuilding is really a mind game; only those who are patient and focused achieve their goals.
Genetics does play a part; there is no doubt about it. Some people are predisposed to physical fitness while some are not. That does not mean that they are stuck like that forever. They can succeed in their fitness goals but they need to work harder at it. Genetics simply the directs the speed of your development. Fast results are great but slow and steady is just as good.
So don't blame your genetics for your failure. Train your mind to think positive; if you do, then your body will respond to that positive feeling. Don't let failure get you down. Always try to stay positive, encourage yourself, tell your mind and body that you will never give up and you will succeed.
Train hard, be hard!