The 4-row arrangement packs those 10 circuits into a shorter header body than a 2-row equivalent, which helps when board real estate is tight along one axis. That extra material gives the contact beams more wear margin during insertion and better corrosion resistance in mildly humid environments. The through-hole mounting keeps the header mechanically anchored to the board; there is no surface-mount joint to crack under cable strain.
Comparing to the 16-Position Sibling 1-216791-6
If 10 positions are not enough, the 1-216791-6 offers 16 positions in a 2-row layout at the same 0.100" board-side pitch. The 5111595-1's 4-row, 0.075" row spacing gives a denser footprint per circuit — useful when the board length is the constraint.