Secondly, it is supposed to be used in a situation where the US parent company wants to transfer a member of staff from an international office.
I'm not sure to what extent the DHS look for the nuance of it being a US based PARENT company (which is not the situation you are actually describing) but I know that when international companies want to open US offices they often go down the E2 route, especially as they can then obtain visas for other employees of the same nationality. But that wouldn't work for venture backed startups due to the >50% ownership requirements.
On a personal level, this is also a crap visa route because you are locked to the L1 sponsor employer - meaning you would have to go home if you no longer were employed by the company (either by choice or by the company folding).