If you had left San Juan, you would find that PR's infrastructure is in terrible shape. The roads through the interior are insanely dangerous, the police are understaffed and corrupt, and poverty exists on a massive scale. Many Puerto Ricans think that becoming a state would mean better infrastructure, more development, a reduction in police corruption, etc. There isn't nearly as much tourism in the interior or even a lot of the coastal areas outside of San Juan, so the people are NOT perfectly happy sitting around collecting tourist dollars.
This is why more than half of Puerto Ricans voted FOR statehood the last time around.