I know what you mean. I've suffered a lot from bad Pinyin trying to find the actual Chinese behind bad Pinyin phrases for Babelcarp. But now that I'm starting to study Chinese for real, I realize that Pinyin as a guide to pronouncing an actual dialect of Chinese leaves a lot to be desired. When trying to figure out how a string of Pinyin should actually sound, you have to run through a mental process involving rules within exceptions within rules.[1] Whether Pinyin could have been designed better is an interesting question, but at this point in history it's probably pointless. But I'm starting to develop some sympathy for native speakers of Chinese who have trouble navigating the rules in reverse, that is to say, from sounds to Pinyin.
/Lew