Don't about the russian software, but for any high-speed PCB design the trace layout matters and 90-degrees bends are to be avoided. On motherboards you'll often see lines that have an extra squiggle or two to equalise the length (and thus delay) because they happened to have a shorter distance to cover.
Mostly 90-degree bends are avoided (in preference to two 45-degree bends) because it makes the routing easier or because it looks better to the person doing the layout. If you are operating with high-enough speed signals that a 90-degree bend is a problem you are also avoiding layer changes and many other things like the plague.
Interestingly, I contend that the prevelance of 45 degree angles is in large part due to the capabilities of ECAD software. If you look at old manually-routed PCBs, 45 degree bends are rare. If you try to make a design with non-45 degree bends in most ECAD software, prepare for pain as much of the features of the layout engine fail to work properly (I had experience of this after being inspired by some images of TopoR-designed boards).
What was that russian electronic board design software where nothing is vertically/horizontally aligned, no trace is straight?