Ryanair going offline on Friday

Ryanair are taking their website down on Friday night until midnight on Saturday to install new software to make the site run fast.  Airlines all over the world install new software and upgrades all the time without having to go offline. Why do Ryanair have to close down everything?  Customers travelling from 4pm GMT on Friday until Sunday morning will not have access to their bookings and will be unable to print of boarding cards.  I hope Ryanair will give some leeway to those customers who did not get the message and