Which part of their ideology do you think conflicts with human nature or practicality? Conservatives obviously don’t completely agree on the details of implementing their idelogy, e.g. the fair tax vs. the flat tax. But the idea of lower taxes and smaller government is based on years of observation about what seems to most benefit an economy. Likewise we support constitutional principles because they worked to make us the most successful country in the world. I think conservatism is more tuned to human nature than any other political philosophy.
I always use the following scenario with liberals to highlight why I am a conservative:
If you had to give total power of attorney over your financial affairs, would you choose a frugal person or a free spending idiot?