There are too many different messengers and their number is growing. Skype, Telegram, Viber, Kik, FB messenger, G+. Each new messenger is a new app, which means:
1. Extra maintenance: installing updates, maintaining security - creating and remembering a password, updating the app, spending time on stupid in-app announcements like news, adjusting to UI design changes that IM developers roll out every fucking half a year, and so on.
2. Extra time spent daily or regularly to check messages in all of them.
3. Extra space on my phone (yes, a that's a limited resource) and extra slowdown if I keep it running.
4. Extra time spent consolidating messages in one place (so I could use them in my time management and project management). It's actually an interoperability nightmare. It's hard to move data like text, pictures or videos between different apps. Export-import functions are all different, sometimes buggy, sometimes non-existent. What I often do is I take a screenshot of a message (and it's multiple screenshots in case of a longer conversation) and then I compose an e-mail to myself, attaching these images, so I could get it in e-mail and mark for follow-up.
5. Archival nightmare. With just e-mail I can conveniently search all e-mails from any computer. If I change computers, I can re-install Outlook, move the PST file, and it's all there. Many IMs won't preserve and transfer your chat history. Sometimes they just upgrade to a new version and clear it - there's no guarantee they won't do it. It's also a real PITA to search across apps.
6. Privacy nightmare. A lot of people (in the past - hand-crafted list of contacts, the latest trend - all of my phone contacts) will know when I am online, and will try to "catch me" for a chat. This is particularly terrible, because:
- If I am online, it doesn't mean I am online for you. In overwhelming majority of cases it's exactly the opposite: I am online because I had a pre-arranged chat with someone else, so I am busy and it's a bad time for a conversation.
- People assume that I read what they send me and take action, either creating an expectation that I won't fulfill, or causing me to complicate my workflow and spend extra time transferring their messages to e-mail.
- It bypasses the normal process of scheduling a conversation with me, which is via e-mail. I don't want to give someone a preference just because they're using a stupid IM and they're currently online there. I am not going to promote usage of IMs.