To understand Apple's likely reasons for abandoning support for the original, decade-old Express requires appreciating some contextual knowledge.
When Apple introduced an update to iTunes (iTunes 8), it resulted in many complaints regarding momentary audio dropouts. You can search this site for those reports, which go on for many pages and with many tens of thousands of "views". It is not a coincidence that the original Express had already been discontinued - six months prior to that update - replacing it with the new 802.11n Express (which remains supported to this day).
A number of users correctly surmised that the iTunes 8 update increased the amount of information carried by the AirTunes stream, burdening the limited bandwidth the original Express was capable of to the point that random music streaming interruptions would result. This eventually led a number of experienced users ("über-answerers" to use your terminology) to suggest using the recently introduced 802.11n networking protocol instead of the bandwidth - constrained 802.11b/g. The original Express is incapable of 802.11n. As users migrated to the newer Express with its ability to transmit the greater amount of information carried by the iTunes Music audio stream, the complaints regarding random pauses and dropouts gradually began to subside.
Apple never officially acknowledged the reason for abandoning support for the original Express, and they never officially acknowledged the AirTunes dropout problem, but this much is certain: Apple is never going to bring back support for it, not with Yosemite, not ever.
Perhaps to a greater degree than any other company, Apple understands the requirement to continuously innovate and improve its products is essential to their survival. They will no longer support your Express any more than they will support PowerPC code, or the 68k code that preceded it. To do so will limit their ability to innovate and respond to the market's incessant demand for innovative products.
Technologically, Apple doesn't regress and they don't stagnate. Apple creates, then they destroy what they create. It has always been that way.
How hard would it have been to let people use the old Airport-admin? Not hard at all of course.
Apple has done nothing to prevent you or anyone else from using decade-old technology. You're already doing that with your "half-bricked" Mac (whatever that means) and you can continue to do so, for as long as you wish. Not hard at all. Mavericks "killed" exactly nothing. Your Express still works, and will likely continue to work, within the limitations of its original, decade-old engineering, in the exact same manner as any other Apple product there has ever been. To expect Apple to carve out special code for the sole purpose of supporting an outdated product is unreasonable, just as unreasonable as it would be for them to support the LaserWriter Plus, even though it cost $7,000 (1985 dollars) and may remain perfectly functional to this day.
As for my reply: You seem to assume I was merely being flippant but I was not. It is a completely appropriate answer to the question "Where are you heading Apple?". The answer was as obvious as it is simple - "forward" -and I stand by it. If you still think it was childish, funny, or in bad form, that's your prerogative.
The alternatives to progress are not realistic for any company, much less a technology company such as Apple. Stagnation equals death. If Apple were to abandon their decades-old tradition of constant, unrelenting innovation; to stagnate, or to cling to the past, I'd be the first to leave them and never look back.