The tweaks don't always work without any issues: speakers make static or USB ports get disabled even with wireless mice, for example. Distros don't want to cause problems like this.
Some distros don't offer a laptop-optimized build explicitly. But many times this is because the optimization is performed as an automated step during the installation process.
That said, some popular distros do offer laptop modes during install. Off the top of my head, I think Ubuntu and Gentoo do.