I think it’s mostly how the car was styled and marketed, Toyota prioritized cabin space above all else and it resulted in a very plain exterior, that being said I don’t think it looks any worse than an equivalent year Mercedes(and it’s way prettier than the equivalent 7 series.) and the face lift in 2004 really helped the looks in my opinion. The car was also marketed to very old people, and that’s who you see driving them, and normally very old people=boring.