With all due respect, you can't say you didn't even slightly expect this sort of issue. Every single one of us knows the general consensus when it comes to snakes. People are ignorant. One snake is the same as the rest to them. They don't want to take the initiative to learn about something they fear, so they continue to make themselves look like insensitive morons.
I say that to every person who negatively comments the pic(s), post something along these lines: "How would you feel if I said that about your (insert animal here)?" "You obviously don't know the difference between one snake to the next if you're saying things like that." "If you bothered to learn about snakes, you'd realize you are wrong." These people obviously don't respect your husband (or you) enough if they cannot refrain from making negative comments about an animal that you both obviously love and care for. Not to mention that if they don't like snakes, why are they even looking at the picture? They're just doing it to be rude, is all.