The resistor is installed before the capacitor, so the resistor is only effective during the short interval when the capacitor is being charged. The current during that interval is many times higher than the average current, so the resistor drops much more voltage. It reduces the net voltage many times more than you might expect.
This is a very common mis-perception. You can read classic texts on power supplies, but for many people it is more valuable to see it visually. You can download for free the "PSUD" program from the Duncan Amps site; it is an excellent simulation program which can be surprisingly accurate. It will take some effort to learn to use it, but that effort will pay major dividends in understanding. And once you understand how to use it, you can try different configurations easily and broaden your understanding in ways that would take years if you just built things.
http://www.duncanamps.com/psud2/index.htmlOn the Audio Asylum, especially the Tube DIY forum, there are many threads on using PSUD. My own advice is to be wary of threads that go on very deep, as they are too often flame wars, but otherwise there is a wealth of hard-earned knowledge available there.