I've noticed this too. They're standards drop once they get older, smell the qaxwo, and see the real world. In university, Somali girls are very unrealistic.
this is gonna be long winded but here goes...
somali girls (like men) generally enter their early to mid 20s as naive, and insulated individuals. their social circles at that age are usually exactly what they are. they don't have opposing views so they create these echo chambers where all their sentiments are mirrored back.
once they hit university or the work force they have no choice but to interact with others and they can see how unrealistic those expectations are when they can't actually find that dude they're looking for. so i wouldn't say they settle, they just realize what they want isn't actually a thing and what you sacrifice in getting that 6'6, 220 pound dude in a bentley far outweighs the inherent benefit.
they basically start scrutinizing their own wants and needs and the question of "why do i even want this?" starts to seep in. same thing happens to the dudes that truly believe they can land some gorgeous model that is willing to stay at home and raise the kids whilst staying faithful so they can venture off to marry wife number 2 or focus on their career 24/7 leaving her to tend to kids. those expectations crash and crumble when you fully understand the severity of those actions and people start realizing that ain't really what want or need.
most girls just fall back on to the physical appearance and personality traits they want (within reason) and drop the extra shit like a 6 figure income and nice car. the niggas start looking for much the same.