That is an interesting strawman you've constructed, as accepting it requires the reader to conflate the idea of bugs in general and "fatal flaws".
Obviously all non-trivial code working in production not only can have bugs, but will have bugs. Just as obviously, no reasonable person would consider those "fatal flaws" for any reasonable definition of the word fatal.
MRI/YARV's Conservative GC opens up some bedevilling classes of bugs for gem writers, obviously. Calling that a "fatal flaw" when millions of lines of production code continue to function despite its presence is nothing but over-the-top hyperbole.
