There will always be people who are crabby, obnoxious, bitter and mean. Just as there will always be people who are decent and honest and happy. Whether you are adopted or lived with your biological family, you will be a product of your environment and circumstances. Let's face it - the percentage is probably higher that there are more biological crappy parents than adopted ones....it's just numbers. But there are good and bad and whatever you wound up with is what you had and that's the past. Don't blame anyone...be who YOU want to be.
I think it's funny when people are really negative. I'm a "pull yourself up by your bootstraps" person and can't stand the whiners (as you all know)