You should also take into account that internet speeds of that era were not as great. Today, we download multiple megabytes of javascript. Back then downloading the same multiple megabytes of java was slow because of network.

At least that was the case for me...

I always wonder -- if Sun had forced people to build their own loading screen UI per applet -- how the perception of Java (and Java Applets) would be different.

It's worth remembering that Applets were active at a time when the Internet, as a whole, was a lot slower.

Although yeah, even with our newfangled fibre connections applets are still pretty bloated.