There are already some plugins that "staticize" your website, but
1) you still need to have and maintain secure the WordPress Installation somewhere. With HardyPress WP can be paused and restored when needed with a click.
2) you have to download the static version and upload it somewhere else manually (your client certainly can't do it on their own). HardyPress does it with a click.
3) contact forms and search will stop working. With HardyPress, if you use CF7, everything will work seemlessy.
To solve the problems above HaryPress needs to hosts your WP installation.
1) you still need to have and maintain secure the WordPress Installation somewhere. With HardyPress WP can be paused and restored when needed with a click.
2) you have to download the static version and upload it somewhere else manually (your client certainly can't do it on their own). HardyPress does it with a click.
3) contact forms and search will stop working. With HardyPress, if you use CF7, everything will work seemlessy.
To solve the problems above HaryPress needs to hosts your WP installation.