Q 'fashions' and sizing

I never ( well VERY rarely) buy any clothing item from Q, mainly because most of it I just don't like BUT why do they often talk about the style etc. & mention the garment measurements almost as an after thought? It must be a lottery trying to get the right size.How many time have you ordered something & if in a shop would have tried a size up/ down to get the right fit? It is no good the likes of Debbie F saying 'I am a 14/16 so would go for a large in this range'.