But some of this clever guys (I don't know who exactly), was able to modify original mmc code to make it impossible (now) mine mmc with GPU.
The coding for MMC2 was not changed. If I remember my early months of 2014 correctly, the Radeon HD 7970 or Radeon R9 280X produced ~20HPM at around 350W. The i7-4770K initially produced ~3HPM at less than 90W. When yvg1900 released YAM, the i7-4770K jumped to ~13HPM. GPU miners simply could not compete with the power efficiency of CPU miners when they are between 2 and 3 times more efficient. AES-NI FTW!!! On a similar note, it is normal to see a dual socket Xeon servers pushing 40 HPM when using YAM. The problem right now is that all the default pools are down and YAM stops mining when it is unable to submit shares for the developer.