Because they wrote it in an era when internet connections were slow. They have not necessarily moved along the time-to-load-vs-page-size tradeoff curve so much as the curve itself has shifted due to improved connections and computation speeds.
It's like looking at a newspaper from a century ago and remarking "how much cheaper it was back then!" Technically you're right, but the change in nominal price is not a useful economic indicator.
A newspaper a century ago is an excellent analogy.
Then, the front page was filled with advertising. The content was almost entirely sponsored, or in times of war or national fraction, overwhelmingly towing the official line.
Newspapers a century ago are exactly the same as popular web today.
It's like looking at an article from a news site today, and being presented with a splash-screen 5-second advert, or not being sure who sponsored the content you're reading.
100 year old press is identical to web-news today.
It’s around 64 KB, which means around 10 seconds load time on a modem, if I remember correctly. That’s very comparable to the current state of affairs.
It's like looking at a newspaper from a century ago and remarking "how much cheaper it was back then!" Technically you're right, but the change in nominal price is not a useful economic indicator.