Confining pets in small spaces

Yesterday I saw a question on Yahoo Answers from a girl who was getting a kitten. She said her dad HATES cats but as she's his 'lil girl' he said OK as long as the kitten stayed in a cage until she grew up. She went on to say that of course she'd let the kitten out for a while when she was home from school but it would have to go back in overnight.Was that OK ? I was astonished to see some answers saying yes that was acceptable !
That kitten would be shut in a cage for at least 18 hours out of the 24 hours in a day and with no companionship.Poor little soul, leaving her mother and siblings and condemned to that life.I pointed that out and that kittens need regular feeding and interaction with people and fun and games, they did not need shutting away alone in a house ruled by someone who hates cats.
What is it with these 'kitty cages ' and 'dog crates' I can't understand why people get pets and then lock them away for hours on end. Here in England our pets have the freedom of the house and the garden at the very least ! Pets are not possessions to be taken out of cages or crates when it suits.It's not compulsory to have a pet, so why why why do some people take them and possibly deprive them of a loving happy home where they'd be one of the family ?