Yes, NASA should spend more resources on exploring other planets, because NASA is a very exciting part of the U.S. government. We learning things that are amazing. We learn more about the universe we live in. The more we learn about the universe, the more we can learn about how we got here and what our purpose is.
NASA has done a magnificent job exploring Mars. We're all lucky to be alive in a time when we can see pictures of what it's like to be on another planet. Thus, they should continue to do this kind of research, and expand it to the reaches of the other planets. Specifically, we need to continue to search for life. Doing so is the ultimate scientific achievement that could change humanity forever.
We are in the Milky Way, which we know to have nine planets. One of those planets has life. There is an uncountable amount of galaxies and planets, so yes they need to try to study other planets, because the odds are we are not the only planet that has life.
NASA should explore all of the planets that it wants, but budget cuts mean that they are only focusing close to home - mostly Mars, and often asteroids or other planetoids in the nearby area. NASA should not be constrained by strict parameters because people don't understand what they contribute.
NASA should spend more money observing the Earth because this is the only planet we have to live on right now. With global warming and larger superstorms wreaking havoc, it's time humans try to preserve our own planet before trying to figure out if other planets are habitable. It's nice to know what else is out there, but Earth should come first.