And they do not use the keyboard to move the mouse.
I talked about using navigation in Main Menu  using keyboard (Tab key etc), this is requested by Accessibility law regulations in EU and US. Whether the customer wants to or not is irrelevant, this is the legal requirement, especially for government & community services sites.
But I agree, that click to open submenu may be needed in some cases. I will ask about that too. I know Astriod framework. Thanks, we will be in touch. Ping me at the middle of month.