I have been seeing this as well for the past year. It is worse as we ramp up the number of users we have. I opened a ticket with VM Ware support and they had me do the following:

Remove all VM Ware software (agents and tools)

Install order for gold images-

1)Upgrade VM Ware tools to 10.2.5-Custom install without SVGA driver. Reboot
2)Horizon Agent Install, reboot
3)UEM Agent Install
4)App Volumes Agent Install, reboot
5)Check that the VM Ware Tools, Horizons Agent, UEM Agent, and App Volumes Agents are running.
6)If we have them, the NVIDIA drivers.
7)Check the SSL thumprint in the registry and make sure it matches the *.domain.com SSL cert thumbprint.

The following registry keys should be set in the gold image (the 5000 number is arbitrary and can be changed to fit our environment)-

Hive         HKEY_CURRENT_USER
Key path     Control Panel\Desktop
Value name   AutoEndTasks
Value type   REG_SZ
Value data   1

Hive         HKEY_CURRENT_USER
Key path     Control Panel\Desktop
Value name   HungAppTimeout
Value type   REG_SZ
Value data   5000

Hive         HKEY_CURRENT_USER
Key path     Control Panel\Desktop
Value name   WaitToKillAppTimeout
Value type   REG_SZ
Value data   5000

I have also looked at upgrading to 7.7, but support said that 7.8 was coming.