I appreciate much of what folks have posted here, but there are some points that need to be considered:
Apple doesn't, and never intended, to provide all of the solutions to all users. They create products, yes. They provide development environments for their two ecosystems, yes. They created two non-identical operating systems, yes. But those two OSen are NOT the same thing, much as they may appear to be. The AppleTV is an iOS device (like the iPad, iPod, iPhone) -- we all know that. That environment is NOT the same as the Mac OS.
I'm not thrilled that Apple didn't produce a Remote app for the MacOS, but as others have pointed out, there are developers who have pieces of solutions. I've found nothing amiss with 1keyboard for my typing needs -- it's only missing navigation. Maybe it has features in the pro version I am unaware of, as I'm using the trial now. I like what the developer has done thus far, and hope they continue with a navigation module next. Then again, I've learned that the last thing I want near me while I watch something through AppleTV or listen to the family music itunes machine is a computer -- I spend FAR too much time on one as it is, and prefer to focus solely on one media form at a time. That's a new paradigm for me, but I am finding I like it much.
More importantly, this forum (and most online resources) are largely ignored by Apple. If you want to gain attention, you need to use their feedback forms on this website. Squeaky wheel is really part of their culture. You want to really get attention, go into the store, buy something (AppleTV, highest end MBP you can afford, etc.), take it home -- then take it back to the store for a full return a few days later. Ask to speak to the Store manager -- not just the manager or supervisor on duty -- personally hand the kit back to them with a very civil, very polite, very firm reason why this combo of product is not working for you. Express your disappointment, and ask them if they can recommend an Android solution of hardware and software that would do what you want. Repeat as desired.
I'm not suggesting you unwrap the devices, and certainly not break the factory tape on the boxes -- just a purchase and return. Do that several times if you wish to be an activist. Fussing here will get you absolutely NOWHERE. Only what occurs at the retail end and to a much lesser extent the feedback forms gains any attention from Apple. And even that's iffy based on my experience in trying to contribute to the server OS product line (basically crippled and dumbed down to the 4th grade level ever since its high point with 10.6).
My opinion. YMMV.
