Why does everyone say that the blinds are losing positions?
It’s a mathematical fact based on tens of millions of hands that the small and big blinds are the biggest losing seats at the table (from analytical research provided by www.badbeat.com).

The reason is mainly down to one thing – the fact that everyone gets to see what you do before you act. There’s also a second reason – the ego factor. This is where you don’t like giving up ‘your’ blinds in the belief that other players are bullying and stealing from you.

The combination makes it a losing proposition.