The entire defense/post boils down to this line:

"... I ought to be more concerned with where the trend in memory is going rather than where it has been."

The problem with this line of argument is that it never ends. Developers who accept this line of argument are always aiming five years down the road, and thus always delivering a poor or substandard experience to their current users.

Your future users are not real, and if you're always targeting future users you're never targeting real people.