This oncid came to me as damaged and in need of repair 5 mnths ago , it quickly rebounded after a media change and lots of TLC , not sure of its specific name as it was not tagged .
I see that often. the leaves that are cut off on oncidiums.
It's because those leaves were unsightly with many spots or brown markings. Fungal issues are all too common for oncidiums and related hybrids, which is a main turn off for me, although I love their colorful (and often fragrant) flowers.