Certainly, everybody has their own opinions on what the government should and should not pay for with our tax dollars. You have things like GPS, which are used by everybody, including the military, and so there's a logical thought that tax dollars spent there makes sense.
For charts, the FAA previously funded the chart production through sales and free distribution. While I do agree that's a nice way to do it overall, the end result is that those of us who used to be paying into the system in the form of chart purchases are now not, so the FAA needs a new funding source. They propose a funding source that mirrors the previous funding source, and people complain because they aren't getting their free Ham Sammich no more.
Point is, the FAA isn't out of line in figuring out a new way to fund this, rather they're being responsible (more of our government should try this concept). I wouldn't have an issue with it being funded in the form of an extra fuel tax or the like, either, since that keeps it getting funded but still allows free access for the beneficial reasons. But really, it comes down to having to get paid for somehow.
What makes no sense is people who don't see why this does need to get paid for somehow. The theory that "I pay my taxes so I pay for it" clearly doesn't work given the current fiscal situation. Something has to give, and while I believe that it should all come from entitlement programs, this, in effect, becomes one if we don't have a designated funding pool.