Ah yes, badge engineering. Canon is by far the most ridiculously greedy company in photography.
While I understand your frustration:
- if you've held one of the cine primes in your hand, you'll realize that a strict re-housing would be least twice the L price. Build is that much better
- They are not the same glass optically. While the differences are minor, even small differences get exponentially more expensive at the top levels...
- The cine series are much smaller and that takes its toll as well
It adds up.
I AM surprised though, that a company such as Samyang/Rokinon isn't all over the 'cine glass' trend. They immediately need to re-house their already re-housed cine lenses into similar fat steel beauties.
There seems to be plenty of market space between normal glass and the $5000 mark for Canon/Zeiss.