So I could see an issue with someone writing business logic in a view and then someone else rewriting that business logic somewhere else slightly differently.
But I've seen the same thing happen in the SPA. Where one person calculates some value in an API method, another doesn't know about it and calculates it again slightly differently in a different method leading to app inconsistencies. And SPA's make it worse not better because it sometimes forces you to write a piece of domain logic twice, once for the browser and once serverside.
I honestly don't know what's wrong with accessing query strings or session information. But I think maybe the reason you've seen template code using global state is because the template code was just written earlier back before that information had really soaked into the entire development community.
But I've seen the same thing happen in the SPA. Where one person calculates some value in an API method, another doesn't know about it and calculates it again slightly differently in a different method leading to app inconsistencies. And SPA's make it worse not better because it sometimes forces you to write a piece of domain logic twice, once for the browser and once serverside.
I honestly don't know what's wrong with accessing query strings or session information. But I think maybe the reason you've seen template code using global state is because the template code was just written earlier back before that information had really soaked into the entire development community.