Michal Hrabanek told in latest issue of Motorsportmonday that there’s two reason why Skoda is WRC2 instead of ERC.

http://digital.motorsportmonday.com//launch.aspx?eid=5861e3ed-ab6c-46e5-adc1-c8f504be4b1c (page 63)

1. Speeding up the development of the Fabia R5. WRC2 events are more demanding technologically than ERC.

2. No manufacturer championship in ERC.