Well, I guess face to face friendship doesn't cover looking at the facts either, Tamara. Sorry but let's do some critical thinking, k?
Looking at your post, correcting many many many many of the design flaws isn't a "good enough" reason to switch systems?
I mean, hell, let's see, what are the advantages:
G36/ XM8 - True modularity allowing for spiral upgrades. That's Ingrish for "you can remove the part you need to and swap it out for something better without major tools". Most assemblies replacable by the operator.
M16 - You can sorta switch stuff by swapping uppers / lowers, necessitating multiple entire assemblies instead of loose component parts. Anything more than that requires depot level maintenance.
ADVANTAGE: G36/XM8
G36/XM8 - True ambidextrous operation out of the box. Selector switch, mag release, charging handle, etc all are mirrored.
M16 - Charging handle is ambi. Mag release & selector are available as add-ons, do not come standard.
ADVANTAGE: G36/XM8
G36/XM8 - operations system doesn't direct fouling into the mechanism. IE, it don't crap where it eats. Headspacing not a problem. Suppressor doesn't affect function.
M16 - ummmmmm, should I even bother?
ADVANTAGE: G36/XM8
G36/XM8 - can take current 5.56 ammo & magazines. Changing to 6.8mm or .300 Whisper (oops, maybe I shouldn't mention that) isn't a problem thanks to design.
M16 - pretty much stuck with 5.56 & 6.8 because the system is constrained by the magwell / magazines.
ADVANTAGE: G36/XM8
G36/XM8 - Integrated optics make everyone a designated marksman
and can be seamlessy upgraded. Option exists though to just put iron sights on for base models. (My vote)
M16 - Iron sights are the base model. Optics require, you guessed it, different uppers, or all sorts of third party workarounds. Upgraded ammo renders built in iron sight units USELESS at long ranges.
ADVANTAGE: G36/XM8 though in my opinion it's more of a draw.
G36/XM8 - Stock can be changed to whatever you want in the field (XM8) or folds completely (G36) Stock breakage has occured with G36 stocks however IIRC.
M16 - Buffer tube requires minimum stock length. Stock not user replacable.
ADVANTAGE: G36/XM8
There's more and more and more, but the most important thing is that this provides a BASE for now and future operations. The M16 is pretty much a dead end, we've done just about everything we can to it; continuing to make changes to it in the long run will wind up costing MORE than switching out the entire system because of the nature of the beast. The XM8 was designed to be upgradeable in every aspect, the M16 wasn't.
There comes a point where you can continue to throw money away trying to fix your old system, or spend money on a new one and save yourself the cost of more "fixes" that should have been organic in the first place.
The G36 has been in use for 10 years or so, right? Let's give the designers some credit - they probably said something like "Hey, the M16 is the most popular system out there, how can we make a better mousetrap?" and worked from there. Not, "Hey, let's just come out with a new rifle for the heck of it - someone will buy it because it's just HK!!!!!1!1LORFL"