In less than 100 years, we will have electromagnetic wave transportation (see Michio Kaku, Micheal Bluth and Einstein). Just need to make a transport mechanism, large vacuum tube. You'll be able to move from one point to another at almost the speed of light.
So the question is, do we waste all this money on Mars Missions and Ionic energy to move the space ships, when in less than 100 years you can take the trip in 10 seconds rather than 500 earth days. Maybe the technology for the transportation apparatus needed for the electromagnetic will be developed with the Mars missions? Maybe the effect on our bodies in space can be perfected? Maybe terraforming another world can be experimented on at Mars?
Maybe this technology will be necessary when we pinpoint goldie locks planets in other solar systems/galaxies/universes/star systems that aren't perfectly inhabitable. Maybe the coming techology works hand in hand.
On the other side, we haven't even explored 70% of our own world that is the ocean. We haven't even explored some of our land mass. But we want to go to a planet and build another civilization when we haven't even learned all about this one yet? Maybe the technology gained in outer space can be applied to exploring our ocean depths?
There are so many pros and cons - timing issues, money issues, taking care of mankind here and now/ or later.