It's just the same process of back formation that led to the -holic suffix as is chocoholic, etc. It's perfectly normal, even if it is irritating. Basically, as a society, we've gotten to the point where the English language needs an one syllable affix instead of a six syllable phrase to indicate a "political scandal" and -gate has been chosen. Live with it. The English language is still a living language and it doesn't always grow in ways that are logical or euphonious.
Yes, just like we need to ensure that all postal workers are gruntled.