'Acceptance' in this sense means 'Easily accepted by a software development community.'
- The name of the methodology gives one a fairly good sense of what the motivation for the methodology is all about. Examples: RationalUnifiedProcess connotes that the methodology is an attempt to unify other disparate methods. ExtremeProgramming fails to convey that the methodology is motivated by the desire to reduce risk (the name seems to imply the opposite at first glance).
- The name does not have an immediate negative connotation to most people. Example: DontCallItExtreme.
- Explaining the basics of the methodology is possible in a short conversation, or a few pages of text.
- Compared to 'chaos', the methodology increases the likelihood of delivering good software.
- Etc...