Zip ties are a custom installers best friend. The perfect way to deal with strain relief issues.
I am sure we will see several different HDMI connectors at some point down the road, just as we now have ... what... 3 different USB connectors?
None of which 'lock' in place.
It makes no sense that they don't have any 'locking' capability as HDMI is not something you plug and unplug all the time, but the success of other plug-type connectors is typical of the industry. There is no reason to use RCA over BNC connectors, but nonetheless, RCA is the standard and most people wonder what a BNC connector even is.
I personally don't care, I've got a good couple of hundred zip ties at my disposal.