Thats by design. The moon could be done in the relative short term with existing technologies. Mars is a tougher nut to crack. So if you abandon Moon missions in favor of supposed Mars missions, what you really do is kick the rock down the road, without admitting it.
If we skip doing “practice missions” on the Moon, couldn’t it be argued that it would save money? Because such an effort would not be well-funded (that is, not as well-funded as it should be). Because other than engine maneuvers, you can do just about everything on the Earth than you would be doing on Mars. Several “Mars analogs” have been found on our planet that to vaying degrees model the conditions on the Red Planet. It’s not as sexy as going to the Moon, but it still gets the job done.
Yeah, maybe.... but it also makes a great deal of sense, if you're serious about more than just a rock-picking tour of Mars. It's a lot easier to use the moon to try out and perfect the techniques and technologies needed for a long-term Mars habitation. And once you've got that infrastructure on the moon, Mars becomes a lot easier. And not only that, but you open up a lot of other places in the Solar System as well.
The real problem -- which folks in the space biz hate to acknowledge -- is that there's no pressing reason to send people to Mars. It'd be cool ... and really expensive ... and there's no particular scientific goal aside from being able to maintain breathable air for a couple of years.