Many, many people do. Many people take the "They're paid multi million dollars to play a kids game??!?" route. I've heard it many times, and to an extent, they are right.
No, they're not. Professional sports stopped being "just a game" a long, long time ago. Pro sports is big business, so big, in fact, that the government grants them certain antitrust protections (this has changed slightly with the recent SCOTUS decision, but they're still huge).
Why should they get paid more than people who actually help the world out?
Because of this:
Supply and demand.
Athletes are worth what they get paid because they (in theory anyway) generate a profit for their employers.
A free agent is free to sign with the highest bidder. What the free market place is willing to pay for a product, service, or employee is, by definition, "worth."
If a team owner pays his players, coaches, staff and overhead $100 million per year, and his total income, through TV contracts, ticket sales, and merchandising is $120 million per year, that's called "profit."
Remember the only source of revenue for professional sports is the fan! Every time you but a ticket, a jersey, or a pepsi, a portion of your money is going to Brian Urlacher, and Julius Peppers.
If athletes are overpaid, the only people to blame are the fans, who consume the product that the athletes put on the field.
This take is a little off in some areas, but for the most part it is spot on. For instance, fans are not the
only source of revenue, at least not primarily: advertising and TV contracts constitute a good portion of teams' revenue, and while fans' interest generally dictates how much teams get for advertising/TV rights, they aren't necessarily the
primary source of dollars in this sense.
And to go a bit deeper, saying the fans "consuming" the product is what drives up ticket prices, player contracts, overall revenue, etc. is a bit simplistic. It's true in the literal sense, but what we really have to look at is what allows those fans to "demand" and "consume" the professional sports "product".
Take ticket prices, for example: sports organizations can be considered rational price setters, meaning that the price point they set for tickets (and merchandise, food at the stadium, etc.) is supposed to be the highest they can reasonably charge for goods without seeing a greater loss from lost sales than they see increases from higher prices.
And generally, it seems that teams in Chicago do a pretty good job at this: the Cubs and Bears, IIRC, have raised ticket prices annually for the last few years, but have seen little-to-no drop in attendance to their respective events. This might not be the result in
every case of teams raising prices, but in general the practice has shown to be sound (we only need to notice that the practice continues to see that it is working, that is unless a majority of sports franchises that are apart of multi-
billion dollar industries are laughably stupid at setting price points and performing cost-benefit analysis).
Furthermore, studies have shown, at least in baseball, that while high salaries don't tend to raise ticket prices, high ticket prices do tend to increase salaries across the board.
So, we have seen teams raise ticket prices, attendance remain at least stagnant with the hikes in prices, and increased salaries as a result. So who is to "blame"?
Answering "the fans" will grant you partial credit, but to get at the root of the issue we need to look deeper: who is putting this money to spend on sports in the pockets of fans?
A good place to start would be the federal government of the 80's and 90's, which oversaw economic booms and tax cuts like few time periods before, allowing more and more high-income fans to take home even more cash.
This might change with the economic uncertainty we face now, but there is no doubt the government's influence on the economy of this country in the last few decades played a part in constructing the system we see today.