If that's what you want, then build with an earlier runtime that still allows a minimum of API 16.
However, I would advise that you NOT do this just to be everyone's friend. According to
Google Play's Distribution Dashboard, as of the time of writing a minimum of API 19 already has 96.5% coverage, and going down to API 16 only nets you 3.0% more. If you're only trying for API 16 because that's what you need for your Nexus 7, you should just upgrade it to its official Android 6.0 update (API 23).
In particular, the addition of TRIM on API 18 is a major consideration. Devices without it slow down over time, to the point of crashing on almost any app. Your app could easily get bad reviews and hard-to-replicate support tickets for the device's faults instead of the app's faults. I've had personal experience with this on my old Google Nexus (which I just replaced with a refurbished iPhone 6), where I've done at least 5 factory resets over the past 3 years just to get it working properly again. The last was when I patched it with an official 4.3 build, and I haven't needed to reset it again since then.
A market segment that can't purchase a new device or bother with upgrading the OS after 6 years is not worth keeping.