Metro Twitter App Vs Desktop Twitter App

The thing that drives me nuts about the metro apps is that most of them offer less functionality than a regular ol desktop app.
Case in point-
On the desktop twitter app if I copy a link and want to @ people as soon as I type the first couple letters it gives me suggestions. Not with the metro app.


It seems like they're all just stripped down versions of more powerful desktop apps. So why would anyone want less functionality?

I'm trying to make sense of it.

I haven't tried the metro twitter app, I have used the desktop twitter app all the times. I think it very convenient for me.