"Alito and Roberts were both chosen by President Bush"
Alito and Roberts were Bush's SECOND choice after Harriet Miers. What else do you need to know?
Alito and Roberts were both appointed by President Bush. It was a good decision. Get over it.
Excuse me?! Before you excoriate others for their facts, you might want to check your own.
Now Chief Justice Roberts was the first and only nominee to replace the deceased Chief Justice Rehnquist. In fact, Roberts was in the nomination process to fill the Sandra Day O'Connor vacancy when Rehnquist died on Saturday, September 3, 2005. President Bush then nominated Roberts to be Chief Justice, so he still needed a replacement for the retiring O'Connor.
Harriet Miers was, indeed, President Bush's first choice to replace O'Connor. When her nomination failed, he could easily have nominated someone more moderate, but he listened to conservatives calling for one of their own to be nominated. Hence Justice Alito.