Why? There are so many programs (free and otherwise) that handle this WAY better than an add-on.
Totally!!
i always think those multi-function pedals that offer built-in drum machines are aimed at the home/amateur market.
Whilst it is a great practice tool (and we should all use a metronome/drumbox for practice) i'd like to think of all the Kemper units as "pro" devices that focus on "pro" features. Certainly the price point of the player is aimed towards the more serious player. If you can afford a Player a few more ££ for an app or similar is not unreasonable.
I think any additional improvements or use of the available power of the player will aim to bring it more in-line with the bigger prodcuts.
And, I'd had to accidentally have a drum beat kick off in the middle of a gig due to an accidental press of buttons...
just my thoughts,