He's using an old Basic52 ROM with the address bits reversed. Doesn't that make it obvious that he barely knows what he's doing? .... Not everybody wants to do what YOU want to do.

I have no such thought, but when "it is obvious that he barely knows what he's doing" then he should be questioned on the choice.
Here is an issue: if, when questioned on the choice, he would reply with a qualified reason, there would be no problem. This thread contain question upon question that the OP did not answer.

The difference between the OP and the car restorer you have, as of late, taken a liking to, is a) that the car restorer KNOWS what he is doing and b) is not designing, but restoring.

If I/we were to ignore 'outmoded ideas' and just support them, where would the growth come from?

If someone would post "I know this is crazy, but I have a board with a 8255 on it that already run this machine and I need to ..." and the addition was reasonable for the board, I would not suggest a redesign.
However if someone post "I am designing this wonderful thing from scratch and am going to use a 8255" I will immediately ask "why the antique" for two reasons: a) there is no future in such a design and b) if nobody ask why, the next poor sod will willy-nilly ("the recipe is on 8052.com") suppose that 8255 is state of the art.

Erik