I didn't watch ENT in the original run, so probably I'm talking about something that was already discussed/explained 10 years ago.
WTF the Xindi sent the beta version of their weapon to Earth? Scratching Florida did absolutely nothing to reduce Earth's space-military capacity and, most relevant, alerted their enemy of their intentions prompting Archer's expedition. Note that Earth didn't know anything about the Xindi before the attack and so they could have developed the weapon with all tranquility.
The other beta version they made, they tested in a uninhabited planetoid nobody cared about --- and inside their territory.
WTF the Xindi sent the beta version of their weapon to Earth? Scratching Florida did absolutely nothing to reduce Earth's space-military capacity and, most relevant, alerted their enemy of their intentions prompting Archer's expedition. Note that Earth didn't know anything about the Xindi before the attack and so they could have developed the weapon with all tranquility.
The other beta version they made, they tested in a uninhabited planetoid nobody cared about --- and inside their territory.