It's because native programming language will defacto allow you to hack it to its natural limit. A tendency most all programmers have given they even get into programming.
For example with any iterator/loop you may want to filter, or find, or transform. in ruby you have the entire Enumerable API to dig into or Array prototype for js.
a templating language would have to reimplement functionality one by one in an allow list.
it's just fatigue at that point, yet another API i've got to mentally track.
edit: of course if you export the view data "clean" before hand it compels you to not have intense logic in the view. I get that but after a decade+ in product, views are never pure, even just ability to highlight the active tab takes conditional and select logic in a loop.
