Ah, but Venus is far easier to terraform. Nothing short of crashing Titan, Europa, Ganymede and Io into Mars and waiting a few ten thousand years is going to increase its pitiful gravity or restart its geodynamo, which are not capable of holding an atmosphere or resisting the solar wind, respectively. Mars could be terraformed, but never permanently, and given this restriction, why bother with Mars, when if ephemeral terraformation is all you're after, Luna is right there?
Now Venus can be respun, cooled, and its atmosphere converted to N2/O2, and it would be liveable for millions to billions of years, and it would have nearly full Earth gravity. It would also have more available energy.
Sealed living environments could be constructed more easily on Mars than under the horrendous conditions that exist on the surface of Venus.
Talk about terraforming and "respinning planets" is nonsense - we can't even figure out how to live nondestructively in the environment we evolved in, or even deliberately influence the weather. Science fiction fans love these preposterous notions but in reality we have managed trips of a couple of days to walk around on the surface of the Moon and are not on track to do anything more substantial than that in the foreseeable future. We don't have the first practical clue about how to begin to do any of the things you toss out so casually. We do know a tiny bit about building sealed environments. Even to do this on Mars, of course, would be so costly and complex that it's unlikely to happen for centuries, if ever. And again, none of the people who even try to plan these unlikely expeditions propose going to Venus instead of or ahead of Mars.
The word "terraforming" followed by ludicrous engineering proposals involving moving planetoids out of their orbit is nothing more than hand waving.
Very few people are motivated to work toward space exploration even locally and there's no reason to believe that any government or other body would undertake to travel to a distant star. "Oh, look, we have some data indicating that there's a planet that we might be able to live on out there - of course, even sending an unmanned probe that will confirm that will cost enormous sums of money and won't return information for centuries."
Science fiction fans preach to one another that these undertakings are not only worthwhile but "inevitable." The rest of the world gets on with the business of living.
It ain't happenin'. Life isn't Star Trek.