When launched, people had said many things in praise of Google Wave, as it made it possible to use many features like communication, e-mailing, messaging, multimedia management and document sharing throughout a single online tool. To dominate the other giants like Facebook and Twitter Google attempted to start a similar service attached with G-Mail and as it was providing all the features as real time it really get high exposure. Integration with wiki, blogging provide a big push for getting popular. It really become a great tool for project collaboration but as time passed people ignore using this tool. I found following some reasons for the reduction in the popularity of this tool.
Mixed up conversation – As a group of many people is communicating in real time, this created a lot of mix up when communication carried by large groups
Not easy for everyone – People who are not so much tech savvy getting it hard to use Google wave and this made it unpopular among them.
Complexity due to various platforms – Google wave can be operated from various platforms which created complexity among various users.
Haven For Spammers – Spammers started to use it for their spamming activities as anybody can add to anybody and wave at him / her. This gave a huge opportunity to spammers for their spamming activities.