Donating blood is a scam in MY opinion. It is unhealthy in the first place, but secondly the red cross, while they are "not for profit" gets a HUGE amount of profit from taking people's blood and they have so much success just based on making people feel that they are doing a good thing.
I remember reading papers about how back in the world wars in the pacific theater, when there was a need for blood transfusion but no blood, they resulted to coconut water IVs, no joke. Perfectly isotonic to human plasma. There are indeed uses for erythrocyte transfusions, but most of these conditions are due to emergencies related to people destroying themselves through diet, drugs and so on. It's just like people saying that surgeons are so heroic. Sure they are...in about 5% of the cases. The rest of the cases are emergencies brought because of the abuse on one's own body. Yes tragic. Absolutely, but can be entirely avoided by a healthy lifestyle.
Should I feel guilty for not donating my time to drug addict hotlines, or for not adopting starving children from Africa? These are all really horrible things and I totally feel bad what I see or hear about them...however by assuming that donating blood, or money or donating whatever it may be is going to fix the problem what we are doing is reinforcing the status quo. I like the idea of prevention better than reaction.
Sure I can donate my blood but what have I done really? Nothing special. Saved a life...maybe. Or maybe the person that get's my blood is saved for a few days before having another heart attack because they go right back to an abusive lifestyle and destroy themselves.
This benevolence is a relative thing. It's all perspective. Is donating blood or whatever the best solution that one can see for the problem? I dunno. Most of the time I hear stats like "Today one out of every 3 people will get cancer"...as if this is like some given constant. I can promise you I'm not getting cancer. I'm one of the 3 people who will not get it. Should I be interested in donating money to the pink ribbon foundations? Or should I be interested in promoting ways in which we can all adopt and effectively change the damn number from 1 in 3 to 1 in 3 million.
I dunno, it's all perspective. I doubt I will ever donate blood and if I am looked at as a bad person for it...hey so be it. I don't like needles in my arm, sorry. And more to the point, needles in the arm aren't in any way the ONLY way to help the people who are suffering. Far from it. If putting a needle in my arm was the ONLY solution, then yeah...I would feel ashamed. Fortunately, there are far better approaches to helping folks out, and needles in one's arm sucking their blood out isn't one of them.
Just my personal feelings on the matter. So obviously if you ask me if you should feel guilty, heck no. There is no guilt to feel if you are compassionate and you find a better way to help others be it motivation, education, setting an example, etc etc etc...