Unique views or unique IPs should be really helpful for private forums allowing only logged in users' visiting than open forums, IMO. It should be an interesting feature that can contribute more content to the board statistics.
But it's not as simple as what the count of views does for adding up to a counter. As far as I can understand, for the most accuracy in general purpose usage, the script should be able to not only tell visits are from different visitors, either logged in users or guests by IPs and sessions/cookies/etc. if they share a same IP, but remember who has visited a specific page. There are also other concerns on recognizing whether a visitor as a return visitor or a new visitor having a recorded IP in database but it's been a long time since the IP's last visiting.
Looks like WordPress (and maybe all other forum softwares) uses visits and some of its plugins targeting statistics can bring such a feature to count unique views/IPs for each post.
I suggest this content to be posted in Feature Request for MyBB or Plugin Request.
However, MyBB 1.9 would probably not show the
Views
column in
forumdisplay
page by default.