No surprises here, it's Sony. The same company that use propertiary memory card on PS Vita.

The same company that has a weird dichotomy between sometimes using other industry-standard data formats, but at times either succeeding (UMatic, Betacam, Professional Disc, Video8/Hi8) and sometimes failing (Betamax, Memory Stick) to have a dominant media storage standard. And sometimes they have products that accept industry standard formats (I have an older prosumer camera from Sony that supports SD, Memory Stick Pro Duo, and a proprietary flash format that is mostly used to record two formats at once, and they made plenty of VHS VCRs).