When one looks back on the worst all-star picks in the past few years, there are two main mechanisms: representatives from great teams who are only there because of the team record (Mo Williams) and solid starters, but nothing more, who are fortunate to benefit from a lack in quality at their position (Jamaal Magloire.) While the representatives are more about the philosophy of value in the NBA -- the media like to reward winning teams and players with an all-star game, yet it's a game for the fans, not the media, and players are already rewarded with the playoffs -- the solid but lucky starters offer hope in how they can be eradicated. When someone like Magloire is picked for a team, everyone knows it's a mistake, but their hands are tied, they say, because they have to pick a "true" center, and the rules are apparently passed down from God and immutable.
The problem is that not every modern NBA player is tied down to a single position. There are combo guards, and these types are usually too small for a shooting guard but can't run the offense to be a point guard. What's more common, however, is the switch between shooting guard and small forward. Danny Granger, a former all-star, is playing shooting guard for his team because of the emergence of small-forward Paul George. When they were younger, guys like Paul Pierce and McGrady could cover both spots easily. The power of this versatility is that it can eliminate an unworthy guard or forward if needed because there are a required number of slots for each position.
The most common position meld is power-forward and center. A majority of the top big men, in fact, cover both positions with regularity. Tim Duncan is the most well known example of one, although in recent years even he can't deny he's strictly a center. Present examples of guys include Pau Gasol, Al Jefferson, Chris Bosh, Elton Brand, Amare Stoudemire, Carlos Boozer, Nene, Al Horford, and Joakim Noah. Surprisingly, Dwight Howard was one listed as a power forward, and right now DeMarcus Cousins, at 270 lbs and 6' 11", is called a power forward, but that won't last very long. The point is that modern NBA teams don't have an exclusive definition of a center, and instead use some players to cover multiple positions. If some people are so worried about Pau Gasol not being a "true" center because he players with finesse, why then do they not care that he's obviously not a "true" power forward because he's seven feet tall and covers center sometimes?
The solution, then, is to list some players with more than one position on ballot and to get rid of the oddly nebulous "guards" and "forwards"categories. For example, Pau Gasol would appear under both PF and C positions (people would be excluded from voting for him for both spots) and his votes would be combined to compete for either category. While it's a huge advantage for some players, the point is to put the best players on the court, and loaded spots like power forward would be better represented. Also, when the coaches choose the bench players, they could use the more flexible positions to avoid a back-up center with dubious credentials, which could likely happen this year in the west.
Last year Tim Duncan made the reserves, and yes he's still an effective player and a hall-of-famer, but he made it at the expense of a young player like Aldridge. Pau Gasol, despite playing large minutes as a center with Bynum out with injures, was listed as a forward, the same category of Carmelo Anthony and Paul Pierce. Yao Ming's multiple starts would have been mitigated because Duncan had more votes than him in many years.
The all-star ballot makes an incorrect assumption about how guys are used -- that guards and forwards are interchangeable, but centers and power forwards are not -- and as such forces people to make awkward decisions about who plays where that should never be made.