Is it ethical to refuse accepting Syria war immigrants?

No! As much as possible should be done to help people coming from an impossible situation start new lives. I sometimes think that Syrian refugees are somehow thought as not human, because if you had a Syrian friend who emailed you and said "Our road is being bombed, can I come and stay with you for a while?" would you really email them back and say "Oh that's terrible, but sorry, no, because I'm not sure there is room for you in my house, your children can't come to my children's school and certainly you can't get a job here, look you're better off staying where you are. Also, I'd prefer you don't have treatment for any medical problems you might have on the NHS, I paid for that with my taxes and it's all mine." I hope that you wouldn't, you'd do everything you could to give them a hand. It's just the same, but on a larger scale. We should do all we can to help other people, full stop.