Hybrid locks are also bad for overall system performance by maximizing local application performance. There is a reason default lock implementations from OS don't spin even a little bit.
glibc pthread mutex uses a user-space spinlock to mitigate the syscall cost for uncontended cases.
Spinning on a CAS is far more expensive than spinning on most other instructions as well as it affects all core that may try to access that cache line, which may include things other than the lock itself.
Also consider how the system acts under high CPU load. You will end up with threads holding locks when not running leading to the majority of the time you miss the lock you spin all 100 times. This just exacerbate the CPU load issues even more. Hybrid locks are only helpful under lower CPU load.