I almost never get excited for space exploration. I'm all about observation and comprehension, and I vastly prefer deep space astronomy to our tiny Solar System matters.
But otherwise I pretty much agree with you.
I think a manned Mars mission is necessary. Granted we might not get a lot a return from the planet itself, but I think it's definitely needed if humans ever really want to do deep space exploration. The amount of new technologies that will be needed to pull that off will be the foundation for all future exploration. The 8-9 month trip will be a true test of astronaut isolation in psychological realm. A manned Mars mission will require new technologies such as force fields (or shields) that help living organisms survive the solar radiation that will be bombarding the passengers aboard. The Mars rovers have returned great finding, but more importantly, they have given us great insight into what rovers are capable of.
There is also the whole genetics element. I think it would be great if we could learn to engineer plants, and maybe even organisms, that could survive on Mars. Not necessarily for the sake of creating an ecosystem on Mars (which would be awesome as hell), but for the sake of deep understanding of the genome as well as the ability to manipulate it. There are many scientists that believe we could engineer species of that could survive and thrive on Mars, and over tens of thousands of years without human intervention, be completely self sustaining on the Red Planet.
I'm completely on board with deep space observation. I reach a state of euphoria whenever I look at images from Hubble and the James Webb telescope, but human exploration (to me) is just as important.
I think the main reason why I support the exploration of Mars to be so important is because I have a finite time on this Earth. While there is no doubt in my mind that life exists all over the cosmos, I don't think were are going to find it outside of our solar system in my lifetime. I strongly believe there was once (and still could be) life on Mars, and I'd love to die knowing that it's there. We have organisms that live in our polar icecaps. They secrete a natural antifreeze that keeps them in water bubbles within the ice, and use the water as energy. If life took hold on Mars while it was wet, life may have been able to evolve in time to make it to the ice. It could have also retreated underground where it could hide from the radiation that roasts the planet. The lack of geologic activity and the presence of seasonal methane plumes is really intriguing. I would love to know what is causing that.
Solar System stuff can be cool too though. I'd be very excited for a manned mision to Mars and I was even a little excited when I heard the rediculous rumours that the chines or something were planning on setting up a base on the moon.
I hope the Chinese pull it off. The more countries exploring space the better. If they were to plant a Chinese flag right next to the American's flag, think of the attention it would generate. I think people would be furious and suddenly have that interest in space travel reignited.