Earlier quoted context omitted.
Your criticism seems a bit idiosyncratic, to put it kindly. So it doesn't use the flavor of C++ you prefer? Sure, but there's a lot of room for argument about whether shared_ptr or template-instantiation bloat would be good choices for an IoT-level embedded system. Similarly, the fact that it doesn't use cmake seems like more a matter of preference than of actual suitability. As for being supported by ARM, well hey,…
Dynamic memory allocation on an embedded system is pretty bad. Even in desktop applications you should usually try and avoid that. Over complicating the build system is a reason for dropping almost anything but especially this. The whole point of a framework like that is to make things easier.
That's the one criticism I found valid. I even called it one of the "Four Horsemen of Poor Performance" in a pretty widely read article I wrote on server performance back in 2002. On the other hand, over-reliance on static allocation means allocating many arrays/pools for the worst case, even when they couldn't possibly all hit worst case at the same time, and that can be a pretty bad choice on a highly memory-constrained device. (Doing it for the sake of real-time predictability is actually a different issue.)
OTOH complaining about not using templates because of performance seems exactly backwards, and complaining that it's not likely the the project sponsor will port already-open-source code to a competing architecture themselves seems a bit too entitled. When I see a list of negatives that are mostly bogus, and no mention of positives at all, it's a strong indicator of NIH syndrome.