The truth is that the worms will live in their food. And they eat the bedding. When we talk about bedding, we are talking about organic matter that is high in carbon, as apposed to organic matter that is high in nitrogen, which we call food. Bedding also tends to be dryer than food.

If you provide only high nitrogen organic materials for the worms, the bin can get pretty yucky. It will go anaerobic, stink, and form ammonia. Add sufficient bedding, and you control the decomposition process, and the bin stays more pleasant. A thick layer of bedding on top also discourages some unwelcome guests, such as fungus gnats. But if you are using a bucket as a bin, you may not have space for a layer that thick.

If you have access to something that has a balance between carbon and nitrogen, (aged horse manure, thermophilic compost) you can use it by itself. Or switch to a bedding that is less prone to clumping (shredded cardboard, peat moss, coir). I personally wouldn't pay for bedding, so I wouldn't use peat moss and coir. Cardboard may still clump a bit, but not nearly as badly as newspaper. If you has access to a sufficient supply, you might try sawdust as bedding.

I use the traditional sredded paper,cardboard and leaves in a thick layer but I sometimes add small quanities of left over castings to incomplete compost after hearvesting worms and useing most of the castings in potting mix. As you would expect, many baby worms and eggs are still in the casings and start a new population in the compost. No top layer is used,just worms cruising around 40 to 50 gallons of cold compost.
What I have found is;
A. The worms do very well if the compost is kept slightly moist,not enough moisture to hold material in a ball when squeezed.
B. No additional feed required. There is plenty in the compost for worms to eat .
C. Fewer strange critters inhabit the material at this stage.
D. The combination of cold composting and worms yields a better product in less time than if compost is left to finish at it's own pace.
E. Material is more friable than normal worm bin making it easy to move around and hearvest a few worms as you might want for fish bait.
F. Worms overwinter and rarely require supplimental heat. (I am in N. Cntrl Tx with mild winters) I partily credit this to 7 cu ft of material buffering tempature swings.
G. Far less attention and labor is required at the expense of slightly reduced rate of worm reproduction that is more than offset by the quanity of material.

If it is true that fishermen are lazy,this might be a good plan for raising worms. You also have castings for swmbo to convince her the intire operation is a labor of love so she can have nice flowers.

I think that newspaper is commonly used for bedding since the point of having worms is to recycle waste. Most of us have newspaper to use up year round. It is also easier to shred than cardboard.

I buy peat moss buy the bale to use in making plant potting mix along with potting soil. Because I have that on hand its easy to use for bedding along with newsprint and cardboard and I like to have it to cover up their nitrogen food to keep flies, gnats away. Works for me.