The main advantage of Chromebooks is in cloud based web apps that require minimal maintenance by the end-user. With a stripped down and simplified computing experience, there is a mistaken assumption that Chromebooks work well with low-end hardware offering performance better suited to mobile level devices. This is further confirmed by manufacturers that market the idea of Chromebooks as a secondary device for 'basic' computing needs. Thus most Chromebooks offered by retailers come with lower end Celeron processors bundled with a meagre 2GB of RAM that suffices for the marketed light use scenarios. However, Chromebooks can be more than this and the growing web-based tools require more memory, other than an adequate processor that briskly renders and loads large documents from the cloud.
Late 2013 saw a number of Chromebooks with Haswell Celeron processors that offered very good performance, even with 2GB of RAM. Since then, however, the trend has been a move to ARM-based processors (Exynos, Rockchip RK3288 and NVIDIA Tegra K1) and Celeron Baytrail-M processors (N2830 and N2840) that require no fans and extend battery life but offer near 40% decrease in performance compared to the Haswell Celeron. This move compromises the hassle-free computing that Chromebooks are meant to offer with, at times, sluggish performance and longer rendering of documents through Google Docs. While Chrome OS is a stripped down cloud-based operating system, it is closer to a desktop experience that can be throttled with mobile class hardware. The next step from manufacturers seems to further expand in the use of ARM-based processors and low-power Celeron Braswell chips that offer no performance improvements over Celeron Baytrail-M (in fact, performance with Braswell is less than the chips they are replacing).
Seeing the continued trend with underpowered but power efficient chips, then it makes sense for Google to optimise the working of their native apps (Google Docs, Youtube, Google Music etc.) with chip-sets offered by Chromebook manufacturers. Of course, the ideal case scenario would be to complement this optimisation with more powerful processor chips that provide a performance bump to handle most web-based applications e.g. Intel Celeron Broadwell based processors.