i thought decimal odds are universal everywhere
they are but that's only v-bookie, we set up markets using real fractional odds as posted on bookie sites, then mtf site's computer calculates them and posts the profit only. It is not we who calculate odds you know. Probably admins have thought this way it will be easier for v-bookie bettors as not many of them are real money gamblers.
I understand your confusion but you could just ask and not accusing a v-bookie manager for not knowing his job. When you don't know or don't understand something just ask.