Why is science so concerned with finding planets that may be habitable?

“Thanks to new research using data from the Kepler space telescope, it’s estimated that there could be as many as 300 million potentially habitable planets in our galaxy. Some could even be pretty close, with several likely within 30 light-years of our Sun.” (quote seti.org)

Pretty close? You have any idea how long it would take to travel 30 light years with today’s current technology? 45,000. years.

So since we will never be able to see these planets, why the big concern? Are we secretly working on the Star-ship Enterprise up in the exosphere?