BASIC for me and thousands of others was the chance to write some very simple code and see it do something. Me, as a kid, could control a computer:
10 PRINT "Hello World!" 20 GOTO 10
HTML offers the same quick reward system because I write the following, save it and view it:
<title>Hello World</title> <body>Remy waved excitedly</body>
The reason HTML works as the BASIC of the web is covered perfectly by Aral:
The beauty of BASIC was that it was zero-install, ubiquitous, single-tool, instant-reward (interpreted/instant-run).
The browser is the interpreter - instant reward and completely ubiquitous. Forget the arguments that HTML is or isn't a programming language - we're talking about accessibility and ease of learning. HTML has both of those licked.
Kids are way ahead compared to when we were kids. They have MySpace & Facebook pages, they're constantly exposed to the web, and they know about view source. They know how to email a file to friends (i.e. their hello world page), and they'll quickly find a free hosting solution akin to geocities or angelfire - so don't worry, you'll soon be able to find their pink flashing neon web sites, because...
HTML is the BASIC of the web.