For easy file operations there was an option to split view in past, removed by following https://bugzilla.gnome.org/show_bug.cgi?id=676858 .
Putting two windows side by side is not the same. They argumented it would be easier on touchscreen, but especially on touchscreen it's pain. Most common use case is kind of comparision of two directiores. It would involve -pressing F3 to split, moving to parent directory in second split tab. Then viewing files with gedit , making file move/copy on that basis. First drawback is when you do this with windows instead split tabs you must choose nautilis from bar, then its instance if you have two windows(2 actions). Then shortcut for positioning windows on left or manual resize. (3rd action) Then the same for second window. So totally 6 actions in total instead simple F3 key. Very iritating if you need to a lot file operations.
Second drawback is that in addition to neutilis operation we need often another gui tool - webbrowser or editor to make on that basis decisions on files or note something. So we can't simplify that to putting one window on the left and second on the right, need manual resizing. This could be pain if you do it often, especially on laptop with touchpad or touchscreen.
ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: nautilus 1:3.14.2-0ubuntu13
ProcVersionSignature: Ubuntu 4.2.0-27.32-generic 4.2.8-ckt1
Uname: Linux 4.2.0-27-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.19.1-0ubuntu5
Architecture: amd64
CurrentDesktop: Unity
Date: Tue Feb 16 23:12:49 2016
GsettingsChanges: b'org.gnome.nautilus.list-view' b'default-column-order' b"['name', 'size', 'type', 'date_modified', 'date_accessed', 'owner', 'group', 'permissions', 'mime_type', 'where']"
InstallationDate: Installed on 2015-05-08 (284 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422)
SourcePackage: nautilus
UpgradeStatus: Upgraded to wily on 2015-11-15 (93 days ago)
Thank you for taking the time to report this bug and helping to make Ubuntu better. The issue you are reporting is an upstream one and it would be nice if somebody having it could send the bug to the developers of the software by following the instructions at https:/