Hello,
It seems polarimetric SAR tools folder seems missing in latest SNAP.
I’m using SNAP version 8.0.5, OS is Windows 10.
They appear in my installation and I do not use them, so they were installed by default. You should check if you have installed all toolboxes correctly.
Better go to SNAP—Tools—Plugins
In the plugins window install all the available plugins
Yes, clean-slate reinstall helped, thanks!