Leo might have first been attracted to Virgo due to their need for constant flattery, as Virgo's virtues are not normally attractive to the Leo confidence. Virgo's passive and reserved nature frustrates Leo and leads to quarrels.
Virgo is practical and prudent whilst Leo is much more generous, their differences about finances including budgeting and putting money away for the future. Leo lives for the moment whilst Virgo exists in the future - a cause of much tension between them. Leo likes to live life expansively, but Virgo is conservative, frugal and a nit-picker - which puts a curb on Leo's high spirits.
Critical Virgos cutting remarks can wound Leo deeply and puncture their inflated ego. They're both very independent, but Leo exhibits this in a temperamental way whilst Virgo is very private. Virgo simply will not be dominated by dictatorial Leo, and always has its guard up. An ill-advised match.