Why is there so much orphan blocks per day on big pools like yiimp or altminer ?

Hello.

Why is Solaris (XLR) on top of profitable crypto currencies for Nvidia when all of your recommended pools don't mine it anymore ? (or have 0 miners)

Rev. $ 24h says 16.89 ATM but exchange rate is 0.00039 BTC per XLR on recommended Exchange (5.17 USD)? I can't make more than 2 per day on fastest pool with my rig. (seems to be cryptohub) I don't get it.