Wait, first you say that the deductions are to make taxes 'fair'. But then you turn around and claim that the deductions are for 'improving society as a whole'? Well, which is it?
The purpose of government, funded by taxes, is to improve society. The purpose of deductions is to allow individuals to have some control over which causes they support (including ones they're directly involved with, such as higher education). The perception of fairness comes from having that control, rather than being penalized for supporting a cause the government doesn't like.
Let's consider a hypothetical scenario, wherein the government has heeded religious zealots' demands to stop funding abortion clinics and stem cell research. An individual, having control over his monetary support, can choose to privately donate to those causes through appropriate non-profit charities, and take a portion of that donated money out of what he'll give to government. Indirectly, that also acts as a monetary penalty for causes that have government, but not popular, support.
When you deduct your education bill from your taxes, how do you think that loss of taxes is made up?
What should happen, and occasionally does, is that any decrease in government revenue forces a budget cut and a review of spending policies. Programs without popular support take the loss. Today, that would likely mean the NSA and various standing military programs, though I'd expect lobbying would protect those.
As for education specifically, the loss (a few hundred dollars) from my taxes is overshadowed by the government-funded grant money (a few thousand dollars) that I did not need. From the government's point of view, higher education is a benefit to society. I chose to support that benefit directly, rather than letting the government decide which other benefits are more important.
For a more direct example, consider that there is an option on your 1040 to donate $3 to a federal matching fund for presidential campaigns. As I do not choose to support the already-too-expensive campaign circus, I do not contribute to that fund. The "loss" is not replaced.
If they want to be assholes about not giving out money, so be it.
Meanwhile, they benefit from all of the charities' work supported by the government and private donations. It is indeed their choice to provide the minimum of funding, but to do so means they also lose control over where their money goes.
If the only reason you are making charitable contributions is to reduce your tax bill, then how charitable are you REALLY being? Again, I think you just like paying less taxes than the guy next to you.
Honestly, who doesn't want to pay less tax? You should note, though, that only a portion of donations is removed from taxes. Deductions are removed from taxable income, so if your tax bracket is 25%, then your final tax amount will only drop by 25% of what you donated. It is not possible to actually profit from donating (unless you change tax brackets, but that leads into a longer and more mathematical discussion than I care for today). Rather, the primary benefit from deductions is that direct control over where money goes.
I don't agree with ANY of the deductions given to people for their expenses (child care, health care, mortgage interest, etc.)
The society benefits from having parents available in the workforce. It benefits from having a healthy population. It benefits from everyone having a place to live... That said, there are some deductions with dubious direct or indirect benefit. You'll have to take those up with your representative.
I want them all gone so that the tax code is simplified
A silly endeavor, in my opinion. A simple tax code is effectively the government saying "we don't care what you do with your money, but this chunk is ours to do with as we please".
Tax code, as it stands today, really isn't even too bad. I've worked for financial planners, and I've seen some pretty complicated returns. They're mostly just 15 copies of the same form, filled in the same manner with information on different investments. The most difficult part of these returns is actually finding the requested information. Every investment's paperwork is laid out differently. One partnership I saw even gave their required data in essay form. That's what I think should be simplified: Each standard form that the taxpayer sends to the IRS should also have a standard information sheet for the taxpayer to receive. Rather than receiving a 1099 with information, they'll receive the 1099, with information.
stop using it for ... trying to push people to do a certain thing (buying solar, electric cars, etc).
...Because it'd be silly to encourage things that benefit society. That would be far too civilized.