> Because these programs are flawed at some fundamental level.

That's a very strong statement. How do you support it with arguments?

We have strong evidence that anything with 100k+ LoC that uses C or C++ will have use-after-free bugs because of reference semantics. I have no data on D but I wouldn't be surprised if that's the same case there as well. You need to think about ownership and haphazardly treating it as a free-for-all is a fundamental design flaw IMO. Shared mutable state is bad for the same reasons mutable global variables are frowned upon. One needs to keep the sum total of all places and all possible paths leading to them in context for reasoning about any of them. This very very quickly becomes intractable for human minds.