If VMware ESXi disk footprint is small, why is it so big?

VMware ESX 3i, as it was originally known in the VI3 era, was just a tiny 32MB. With VMware vSphere 4, the name changed slightly to VMware ESXi 4, and grew to about 60MB — still extremely small for a fully-functional hypervisor with HA, VMotion, DRS, and all the other vSphere features. With ESXi 5 it is changed to approx 160MB

While ESXi is less than 160MB, installing it actually requires a 1GB flash device.
Most of the time this question is frequently asked if running disk footprint of esxi is so small they why it needs approx 1GB free disk space for the installation what is meaning of this

Not only does a 1GB flash device contain the ESXi hypervisor, it also provides VMware Tools for various supported operating systems and a copy of the vSphere Client which administrators can download and install to their workstations. These components are not executed by the hypervisor at all — they can be obtained through other means, but it is very convenient to have them right on the host. For PoC (Proof of Concept) i tested it with this command in ESXi Shell.