I wouldn't really say that.
My templates are quite advanced and more complex than the Wikipedia
ones, and I've never had to mix html and parserfunctions like that.
Personally, using html tables like that kinda disturbs me.
I was referring to the Wikipedia ones, they nearly all use some form of
HTML + wikitext mix or don't finish tables due to the fact that - more
often that not - the actually included templates are made up of hundreds
of smaller ones. You may well be able to create more complex templates
without doing this (so could many others), but we are talking about
Wikipedia here - not your bog standard wiki.