The Merovigians helped start the feudal system. They were actually weak kings. So they relied on a hierarchy of nobles to help them. To reward these people, they "farmed out" pieces of land to them in a manner that we would now call "fiefdoms."
Feudalism was unpopular because it was an expensive, clumsy way of governing. Most people (in the first millenium) didn't mind supporting kings. But feudalism created a whole CHAIN of overlords, each taking their cut off the backs of poor peasants. (Today's "1%" may be creating a "new feudal system," with a new hierarchy, and if they are resented, this may be the reason why.)
Feudalism made people (specifically poor peasants) wish for "the good old days." The Merovigians brought an end to the "good old days" sooner than kings in other parts of Europe.
Here is a link to a post on another site which draws parallels between the original and "new" feudalism. http://seekingalpha.com/instablog/399221-tom-au/35971-why-a-new-feudalism-is-plausible