It promotes conformity over creativity. The use of authoritarian parenting can lead children to do as they are told not due to respect but due to utmost fear. The price of conformity is the loss of creative potential. Tiger parenting depends on the parent's views of what's correct. If the Tiger Mom is wrong, children can be doomed to thinking in only one, incorrect way. Children reared by a Tiger Mom risk having never learned to think outside the box. Tiger parenting also rear children to be ill-prepared for the economic demands of relational economics. The Tiger Mom prohibits typical childhood interactions (sleep-overs, for example) that are needed to develop social and relationship skills. The parenting she describes does not model negotiating or give-and-take. Her parenting makes it less likely that children will learn to thrive in an economy that relies on relational capital.
They are typically parents who are overly strict and pushy. Usually they are pushing a child into taking on many different activities such as a musical instrument and other extra curricular activities. The more the parent pushes the child into doing this activity, the more the child wants to rebel against it and do their own thing. This can result in a child hating whatever their parent wants them to do. Tiger parents generally push their children into doing things which would arguably be good for them (music, ECAs, extension work) and if the child grows up hating it and being opposed to it, that is bad. Parents who aren't as strict and pushy will raise children who enjoy learning much more and are much more open to new opportunities and activities
That's just my opinion, anyway.
Often, the kids are forced to do what they don't want to, like some interest classes (particularly musical instruments). This can basically lead to worse relationships because if the child has an interest in something other than the tiger parent, it just ends up being scrapped merely because it doesn't match the parents' interests.
The standard is set high, early on. Tiger Mommas demand excellence. As a result, they raise kids who put extra effort into their work. Effort correlates with achievement, but there is not a direct causal relationship between effort and achievement. Hence, the kids achieve better outcomes, on average, than those kids raised by parents that didn't impose such rigorous standards.