1. Sale of 50% of the team (the half originally owned by John Mara since it was passed down from the team's founder in 1930) to Robert Tisch (Loews Corporation owner and former U.S. Postmaster General) in 1991.
2. Death of Wellington Mara in 2005, with his 50% ownership passing to his son John.
3. Death of Bob Tisch shortly thereafter, with his 50% ownership passing to his son, entertainment industry executive Steve Tisch.
4. Items #1 and #2 marked the official passing of the torch from the old "football" ownership to the new "business" ownership, and it hasn't been pretty.
5. Announcement in 2005 of a new stadium in the New Jersey Meadowlands, to be shared with the New York Jets and completed in time for the 2010 season.
6. Complete disaster in the sale of season tickets and seat licenses to fans in 2008-09. The Giants were once famed for their season ticket waiting list, and for years people would put their names on this list in the hopes that their children would be able to buy season tickets 25 years later. The economic collapse of 2008-09 didn't help matters, and many seats remain unsold as former "life-long fans" have abandoned the team in droves due to the outrageous $5,000 to $20,000 cost of seat licenses for "regular seats," and the team's inability to meet the demand for the cheapest seats among fans who had attended games at Giants Stadium, Yankee Stadium and the Yale Bowl over the course of the last five decades.
If the guy who had long been the defining player in the history of the franchise and the greatest NFL player of all time meets a terrible fate in the criminal justice system, then this would surely mark the end of the New York Football Giants as I knew them.
Not really sure why you have a problem with owners passing on ownership of a property to their sons.