I wouldn't say text/template is terribly weird per se, and it's quite reminiscent of Jinja. But what is awful is using a text templating language to generate yaml with the correct level of indentation, and that's where 75% of Helm's problems lie; the other 25% is putting too much logic in templates while working with the clumsy workarounds to text/template having no capability of defining custom functions.

You actually can define custom functions as named templates, but they're definitely not pretty, and would almost certainly push you towards the "just allow us to write code using a normal programming language" side of the argument.