Dolphin slow start time and kfileplaces/bookmarks.xml

[Germano Massullo]

Today on #fedora-kde, user rom1dep complained about Dolphin (KDE 4)
taking ~5 seconds to start. He said that removing
.kde/share/apps/kfileplaces/bookmarks.xml
.kde/share/apps/kfileplaces/bookmarks.xml.bak
solved the problem. Those files contained thousands of lines about old
(and no longer used) removable devices.
Since I am running Plasma 5 and I was experiencing slow Dolphin start
times too, I tried to check how many code lines had my  /bookmarks.xml.
I saw that it contained 7161 lines, for 228 KiB of disk space. I tried
to remove those files, then logged out&in from Plasma, and then I saw
that Dolphin required much less time to start. Removing those files did
not affect the resources/bookmarks that everyday I use in Dolphin.

Do you confirm that removing those files reduces Dolphin start time?
Why do they contain all that stuff about unused removable devices? I
could see lines of XML code about Fedora 16