1) I love the tradition and sense of history, and I admire the Queen and her devotion to duty
2) They are a unifying force for British people and above politics
3) They are a major international draw
4) Their charitable work is amazing and their loss would have a devastating impact
The history will always be there - People still visit historic sites regardless of whether there is living royal there - think Stonehenge, Hampton Court, Edinburgh Castle, Scara Brae etc etc
The queen's 'devotion to duty' - she is exceptionally well paid, pandered to and money worry free. A job for life for herself and her bottomless pit of heirs.
They are not unifying - believe me, many want them gone as much as you want them preserved. Charles notoriously gets involved in politics.
A major international draw? Just like Versailles, The Hermitage, The Pyramids and The White House? No royals live there yet tourists pour in.
Many people do charitable work (the real work, not ribbon cutting) and do not get to live for the rest of their lives in luxury. Andrew's nonsense shows how his 'charitable involvement is not welcome, and that some even earn HIM money.