People can be very sensitive about killing (what looks like) baby animals, so I wouldn't be so sure nobody except dragon enthusiasts would have a problem with killing a hatchling, chromatic or no, as long as it acts/talks like a kid. I'd wager quite a few would be displeased if killing it was the only way, with no option to leave it alone or let it go. Hell, many would probably want to "adopt" it like the owlbear cub instead