The portfolio does not allow you to compare one candidate against another and the same guy I had to fire also had a great portfolio, probably like yours and was a good fit on paper. It doesn't tell you how well the person works nor how quickly the person is able to deliver. And quite frankly, no one has time to read through all your code either. And even if they did, how does reading your code help me compare you against another candidate with a completely different set of credentials in an objective way? Without understanding the context under which the code is written, it's useless - I don't know what problems it solves, if it solves any problems anyone actually had, what constraints you were operating under and what challenges you faced and how you were able to handle them. Say, if I were to give you a thousand github profiles, do you think you can realistically rank them in order of how good the owners are?
As I said, this is just not how things are done at modern tech companies and there are good reasons - hiring managers generally don't have the authority to arbitrarily bypass standard processes because hiring managers are inherently biased towards hiring someone good enough for the time being, even if it lowers the bar. So the goal isn't to hire somebody that the hiring manager feels is good enough, but to objectively compare thousands of candidates against one another in a systematic way that keeps the bar sufficiently high enough. You should understand at least what the problem is before you can criticize the solution.
Also, generally speaking, if you pay attention to research into hiring, the two things that really stand out are that 1) general abilities are more important than specific skills and 2) standardized processes outperform ad hoc evaluation. If you're asking to be evaluated on ad hoc credentials that cannot be objectively compared to others (most people's best work cannot be shared) - you're asking people to forego processes. And that is simply not known to work very well, mainly because it's not evidence-based. Your unique set of accomplishments that cannot be compared is not known to correlate with any measure of performance because there's no way to say, people who tend to have accomplishments like yours tend to perform at a certain level.
I also don't know what you mean by "top-shelf" corporation but I'm not aware of any top software company that doesn't basically do this - your claim to have been a hiring manager at a top-shelf corporation isn't consistent with your lack of understanding of the realities faced by top-shelf corporations where there are far more candidates than qualified due to paying well above market and the need to ensure that the bar is kept consistently high, regardless of the motivations and qualities of individual hiring managers and interviewers (unless your top-shelf company isn't actually a software company, in which case it's likely not top-shelf at software).