Plus, word is that Amit is a really great person. I wish I was south asian, so I could help...
modesty: 1. having or showing a moderate or humble estimate of one's merits, importance, etc.;
B) Sure, the design is a little flashy (I think it looks great, by the way), but I don't think he is being terribly immodest. He's not bragging about his accomplishments, he's just trying to get people to sign up as bone marrow donors, and he's using his personal plight as motivation.
The efforts happening on his behalf are, by and large, very consciously being done with this in mind. They are increasing awareness of underrepresented populations in the bone marrow database and making a much larger impact.
Also, these efforts are being coordinated and implemented by volunteers on Amit's behalf. Amit himself is not running this show. People who have better things to do than troll the internet are.