Because that's not what they're being told. I haven't watched, but I assume it's more like "These rapists, murderers and drug dealing gang members are going to be put in a comfortable detention camp that's escape-proof because of the alligators."

I assume they think that it's only the worst of the worst that are being sent to these camps. They believe Trump's narrative that Kilmar Abrego Garcia was a member of MS13 who had MS13 tattooed on his knuckles. They believe that the people being rounded up are gangsters and terrorists, and if there's occasionally a story of someone who wasn't a gangster being deported, they think that's an exception. So, while the detention might be difficult, they think it's literally protecting innocent American lives.