For some clients, people (and their time) can be perceived as being less expensive than tools.Some shops just don't want to spend the money, so you start looking for an alternative tool suite.
For all of these discussions you have to start with a "build, buy, or lease" set of issues included. This of course includes the "buy single vendor, or do the system integration yourself", "is it a one time project, or are we performing ongoing process development", and a lot of other decisions.
Al