GI
If employees have share options then they also double with the split. i.e. Assume you have an option to purchase 1000 shares at £5, total cost £5000. During the course of the option period the share price rises to £10, so Ryanair (or more accurately their Registrar's) "split" the shares and half the price. Your 1000 shares become 2000 but your cost to buy remains at £5000. At the end of the option period you then have 2000 shares worth 2000 x "Current market price", which if everything is still going well should be more than £5.
There is nothing conspiratorial about it. As I said above many comapnies use this as a way to make the shares seem better value. It also means that small price movements look better in percentage terms.