Here’s a list of the files in my home directory:
.adobe
.android
.audacity-data
.autoscan-network
.avidemux6
.bash_history
.bash_logout
.bash_profile
.bashrc
Binaries
.cache
.camel_certs
.ccache
.cgminer
.cinnamon
.color
.composer
.config
.cups
.dbus
Desktop
Documents
dogecoin
.dogecoin
Downloads
.dropbox
.dropbox-dist
.eclipse
.esd_auth
.fontconfig
.gconf
.gimp-2.8
.gksu.lock
.gmvault
.gnome
.gnome2
.gnomerc
.gnupg
.gphoto
.grl-bookmarks
.grl-metadata-store
.grl-podcasts
.gstreamer-0.10
.gtk-bookmarks
.gtk-custom-papers
.history
.hplip
.ICEauthority
.insync-trash
.kchmviewer
.lastpass
.links
.local
.macromedia
.minirc.dfl
.mission-control
.mozilla
Music
.mysql
.mysql_history
Pictures
.pki
Public
.pulse
.pulse-cookie
.puppet
.python_history
.sabnzbd.ini
Scripts
.sickbeard
.Skype
.solar2
.spice-vdagent
.ssh
.steam
.steampath
.steampid
.swt
Templates
.themes
.thumbnails
.thunderbird
.touchegg
.uml
Videos
.vim
.viminfo
.vimrc
.virtinst
.virt-manager
.VirtualBox
VirtualBox VMs
.vnc
.weechat
.wireshark
.Xauthority
.xinitrc
.Xmodmap
.xsession-errors
A vast majority of these files and folders are dot files, and none of them are truly extensions. If I were to use the exclude ability to get rid of those, I would have to do one for each file, and have to make sure to update it regularly if a program on any of my computers decides to make another one of these files or folders.