This is about as strawman an argument out there. Because it is a feedback and/or request, ergo all user requests would destroy the experience, hence this request is not valid. I would disagree.
What many folks are asking for is an option. What some of us are pointing out as a reason for it is the lack of consistency. That's it. This option exists in Mail right now. Has it overloaded settings? I can't see how, personally. It's an option I have if I care enough to want to turn it on, boom--I can. Otherwise, it's there, not keeping me up at night that it's weighed down under a pane in settings.
One observation here is that nobody is saying that there doesn't exist ANY way to resolve both those who have inadvertently deleted messages and would like someone to save their clumsy fingers while remaining consistent with the experience found in other Apple apps.
Apple clearly addressed the former, but was clumsy about the latter.
The two questions I don't see answered by a few of the snarky folks here pushing against those of us who don't care for it is how does adding two more steps to a process make something more usable? And for the sake of argument if one says "yes I believe it actually is more usable", then why isn't it on every other feature in the apps that offer swipe-to-delete without confirmation (like Mail, Notes, etc)?
Would a settings option, a toggle inside messages prefs for the love of ice cream, totally destroy your phone and your experience because it's sitting inside settings waiting for you to go there if you wish? No? Why would adding it to the Mail preferences, where it is now, NOT do this?
Would the option to turn on an ability to recover deleted text messages, or just have a 'trash/deleted messages' option, like you can with voicemail, be worthy and consistent?
My argument would be those options or add-ons would be more consistent than what they did here. Your mileage may differ, but the overwhelming sentiment in the "this is a crappy option" thread is, not surprisingly given the topic, aligned with the argument that it's neither good usability nor consistent.
The former is subjective of course, but the latter is simply fact as evinced in other Apple apps.
Cheers!