Despite the weather is it a tad hypocritcial that people expect blood even though they don't donate blood?

Lots of people can't give blood, so I do disagree with you, but I would translate your point to organ donation. Many people refuse to go on the organ donor register, but would be happy to receive, or for their family to receive someone elses kidney etc. Worse still, a registered donor might not have their organs donated if their husband/wife doesn't give permission. I'd make it an opt-out system, everyone is a donor until they say otherwise.