I would imagine that the widespread use of the National is perpetuated largely by custom and practice. How many new beekeepers adopt the National purely because this is the hive that they have been shown, have done their training on and who are happy to start out on because of 'standardisation'?
Not many new beekeepers will be warned that the National was perfectly suited to a strain of bee that was quite happy with 8 frames, thank-you-very-much but may be inadequate for highly prolific queens.
It didn't take me long to realise that standard national frames were cramping my bees' style. Doubling up on boxes just didn't seem a practical solution (been there, done that) so last year saw me coaxing my bees onto 14x12; much better for accommodation and wintering.
Yes, a brood chamber of frames is heavy but I'm not unduly bothered by that, in consideration of the advantages. It was a good decision.
In a token gesture towards weight reduction (but the main attraction was the apparent sheer practicality) I'm going to try 14x12 poly's this year. I have them painted and ready to be pressed into service. So far (admittedly without bees in residence) I can't really see huge disadvantages (I know, I can't scorch them but thank goodness for a bit of bleach huh?).
Note that my own choice for an alternative was in fact limited by the 'fait accompli' that I had created for myself, having set out with a shed load of national bits and pieces at day one.
Back to Poly's OP - yes, outdated, for me 'n' my bees at least.