Many people agree they are overpaid. But I bet many of those people have bought footballing merchandise which help pay the footballers wages, or bought a ticket for a match, again some of that money goes to the footballers.
A football team is a business, the more client oops I mean supporters they have, the more money they recieve from tickets and merchandise etc etc. So if not so many people supported them, they wouldn't be paid as much. Its not about the quality of the playing, its about the team with the most supporters, who inturn recieve more money who then buy the better players,
Even if all the season ticket holders of some teams (eg Liverpool, Manchester Utd) were to give up their season tickets and never buy a ticket for a game again the club would be able to sell their tickets ten or twenty times over.