I want to make few points quickly in favor of that.
1) No support for programming languages like Java, .Net so that it allows it to be used as an acceptance testing tool.
2) VBSCript doesn’t help in every-one’s participation in the automation process, which is a key in agile projects.
3) No IDE support : QTP’s IDE is no way near Ideal hence makes maintainable a tough battle.
4) NO support for standard IDE like eclipse .
5) Multi browser support is limited.
6) Cant execute scripts on Linux and Mac platforms.
7) No continuous integration support, makes it rally tough to be used as an acceptance testing tool.
8)Test execution is slower compared to other tools, hence makes feedback cycle slower as well.
9) And last but not the least , Bloody expensive
P.S : I am not anti QTP and love QTP as a tool, but QTP is not fit for agile process ..until HP realises that and comes up with solution to rectify the problems mentioned above…..oops that means HP may end up building (Acquiring) a new tool altogether.
Disclaimer : Opinions in this post are my personal opinions and does not intend to pursue any commercial interest. If you think otherwise please ignore the post.