It really seems like a lot of prints of mine would be way stronger if it where done at a angle like that that.
note I 3d print everything all the time. My house is speckled with orange printed parts (I like to point out when something was 3d printed).
45 degree printing is very useful for overhangs in a single direction. This is likely why they've utilized it for printing the bow of the boat.
But this makes printing overhangs in the direction of the nozzle impossible, thus not useful in all applications.
The results depend on the forces your object will see. The tensile strength is lower perpendicular to the printing direction, as the adhesion between layers is lower than the continuous filament adhesion. So printing at an angle is better if you need more tensile strength on the Z axis (but then you can rotate it to have that axis flat), but it also reduces the strength on that angled direction.