I did post these things before in the review section but following this thread and the similar thread in BF I believe that most of the younger people have not seen or used an
older small thin blade wood saw with a single line of teeth, used for pruning tasks etc.
In these saws the thin teeth will be bent a bit in succession to the left or right (L-R-L-R-L-R..) creating:
1. A thicker cutting edge compared to the actual body of the saw blade
2. A channel between the teeth for the saw dust to flow.This way the saw did not get stuck by sawdust congealing and clogging the teeth and the body of the blade always had enough clearance going through the wood, so there was no touching of the sides, so less friction. (a similar system is used in metal saw blades too).
As the saw was used the teeth would tend to align, slowing down the saw and making it stick, so after some time (depending on the use it could be some months) you would use a tool to again move the teeth to the side and sharpening them a bit, rejuvenating the saw.
Modern saws tend to use thicker blades, with two rows of teeth, but again one tooth is to the left then the tooth following in the next row is to the right and so on. The cutting edge is thick and the
body of the saw blade narrows down (gets slimmer) as you go upwards, so the body can move without sticking through the cut wood. This is also the system used in SAKs, multitools etc. This system does not need aligning of the teeth, though it is harder to repair if damaged.
The lumberjack has a single row of, thick, teeth aligned on a uniform thickness blade (From my memory) so for it to work you will need to bend the teeth sideways, like in a traditional saw and to sharpen them.
(or redo the whole saw…) 
If you
only sharpen them then the actual cutting edge will be smaller than the body (pointy edge) and the
saw will get stuck, similar to trying to slice an apple with a thick knife; the body will get stuck at some point and you will need to crack the apple to move the knife through, something that cannot be done with a wood saw, in wood.
The end, going back to my cave now..
