I don't want to text while driving. I hate doing that. What I want is to text with one hand while I'm walking or just at home as having to text with both hands distracts me too much and I end up making a lot of typos or bumping into everything and everyone or even making me completely lose focus of what I was doing before writing the text. It's just all around more practical for me. With all the gimmicky options they're giving to people that don't have any real usefulness apart from looking good 20% of the time (I'm looking at you tile backgrounds), I'd expect them to introduce more things with real utility.
Not only that, but Cortana is a feature that won't be available in Portugal any time soon and if it is it will likely be in Brazilian-Portuguese, much like the voice controls are now. And that is a dialect most of us hate. Still, Siri, Cortana and the likes are things that don't appeal to me because talking to my phone like it's a person is not something I look forward to.