Why is client_max_body_size default set to 1m?

[jlangevin]

After migrating one of our servers to Nginx from Apache, I decided to
test file uploads (as I've implemented the Accelerated Upload Support
feature in PHP-FPM/nginx). I found that
[url=http://wiki.nginx.org/NginxHttpCoreModule#client_max_body_size]client_max_body_size[/url]
is an additional directive that affects POST/upload file sizes.

So this means that in addition to the 2 directives in PHP that must be
configured for upload file size, I must also now configure Nginx as
well?

I can understand this directive existing, but why default it to 1mb?

Found this issue due to this thread and my own failed upload attempts:
http://stackoverflow.com/questions/2056124/nginx-client-max-body-size-has-no-effect

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,139769,139769#msg-139769