Writers from the beginning throw together Penny and Leonard. It should be romantic bond of all serial. But why not watch at him and think: is Leonard good for Penny at all? His character is repulsive in relationship. When he is "sweet"- normal girl should run away and never come back. He always try to screw someone after Penny dumped him( not Romantic or loyal). For instance Koothrappali much more attractive then Leonard with Leonard's high voice, little black eyes, and all his character. Of course relationship with Koothrappali is wrong for serial. But serial is about nerds. And if Penny will be with total nerd it will be very funny. Sheldon is very cute( imagine how shy he can be with someone he likes). Penny can teach Sheldon as a child. And she will have woman’s "button" to switch Shaldon's seizures. Yes Shaldon is total nerd, but why castrate him? He can be a man, a little.