Worth looking at and thinking about.
I respectfully disagree on the overall assessment of M16/M4/AR-15 platform. They do need to be cleaned now and again but nothing crazy. They don't need to be spotless, just have the inside free of junk (chunks of carbon usually being the culprit) and some lube in there. If you are unwilling to do that then buy an AK. As to durability. I haven't seen the Buttstock/ buffer tube of an AR series rifle break during the course of military operations. Like any precise mechanical object they can be broken; I confident it would be easy to destroy any of the old WWII bolt action warhorses, a Remington 870, AK, Glock or whatever in 60 seconds flat by slamming it repeatedly into a rock or a curb. (The exception to this is the old M2 .50 cal because it is too heavy to swing well and has really thick metal components, I would have to take off the barrel and mess up the threads or take pliers to the trigger mechanism which would kind of be cheating).
In my opinion the M16/M4/AR-15 platforms ergonomics and commonality/ availability of parts/ accessories/ ammunition as well as the unparraleled modularity outweigh it's modest negatives.