This really doesn't make any sense.  If I have a small office and I just want two wireless points, you're forcing me to buy three devices even though you sell a router with wireless capability! 
 
There is absolutely no reason to prevent this from integrating other than you wanting to make more money.
 
This is terrible. 
 
I have always enjoyed Meraki devices and platform. I think it's awesome that you have brought the power of CLI to a useable UI and given us what we need to setup networks quickly and easily (albeit with a yearly price attached).
What I don't get is this apparent bizarre decision.
 
What could possibly justify not allowing the two wireless networks to mesh?