While I understand the frustration chair hogs cause, the more I think about the more i realize how difficult it would be for cruise staff to police the deck chairs. There are too many chairs on large ships to track which ones have been "reserved" and for how long.
I think all they really can do is ask that passengers be courteous to one another, something many (passengers) seem unable to do.
All I ask is a tall ship and a star to steer her by; John Masefield
Carnival: Glory 2004, Destiny 2008, Splendor 2009, Freedom 2011, Valor 2012, Dream 2013
Celebrity: Summit 2011
Princess: Ruby 2010, 2014, Caribbean 2013, Coral 2014, Regal 2014, 2016
Sail Windjammer: Mandalay 2017
Star Clippers: Royal Clipper 2015