Venus is ignored because it might as well not exist, due to its Earth-like size and ridiculous surface conditions. All landers sent there have failed shortly after landing (scale of hours).
Its gravity being closer to Earth's is a huge downside, since that means that any rockets taking off would need to be on the scale of the rockets that take satellites into orbit around Earth, if they could even survive the temperatures and pressures. Compared to Venus, Mars is a resort, with low gravity allowing for launching in orbit using much less fuel than would be required on Earth.
Even if you ignore the surface and have people live in floating cities, you have some problems. The lack of surface and natural resources is one. And, you still pretty much need a rocket capable of launching stuff into orbit around Earth since the required orbital velocity is so high.
Mars and the moon are far, far better options than Venus is at this point.
If we're going to colonize multiple planets, eventually we'll have to get over our surface obsession.
We might be able to land on some of the mountain peaks, but I think the distance to Earth more than makes up for the inability to land on the surface of Venus. Though, we might be able to have some automated mining of the mountains.
I think we should at least send more than a few floating probes to Venus. It will certainly teach us a lot about the greenhouse effect. I think we could also have at least a floating lab to learn about the planet.
The fact that you can't mine Venus very easily does mean that the majority of things do need to be shipped in, possibly with the help of mining the moon or asteroids. It is a lot closer to Earth than Mars though, so it's a lot easier to ship things there than to Mars, meaning that once we do set up mining and manufacture on the Moon, it will be cheaper to ship things to Venus.