We had a thread here discussing "changing the default browser", or adding a better browser than Konqueror, you can see the thread in this mailing list archives.

Some of my points were:

1) Almost dead upstream for Konq, vs thriving upstream for Firefox, Konq may have undiscovered security vulnerabilities, but the limited number of users is hiding them.
2) Slower Konq (maybe qtwebkit to blame)
3) KHTML and QtWebEngine not supporting the latest standard (HTML5).
4) The video codecs issue (now, Konq doesn't run YouTube out of the box), even if this bug get fixed, no foreseeable YouTube VP9 support (because MSE) in Konq, VP9 is about 60% the size of VP8 at the same quality and is supported in Firefox and MSE is being worked on.

Then Rex suggested to discuss this in KDE SIG meeting, on Tuesday, 4-8-2015.
In the meeting Kevin Kofler voted against the change.
Daniel Vrátil "believes we should go for Firefox with Konqueror as a fallback", but voted against the change to avoid a flame war.
5 other KDE SIG members voted for the change.

So without a flame war, we have 6 KDE SIG members want the change, and Kevin Kofler refuses it.

Rex asked in a thread for a formal vote, +1 or -1, and explicitly said "Please limit this mailing list thread to votes only, and start new thread(s) if you wish to continue discussing the the pros/cons on the topic.", but the thread got some discussion, and Kevin said "we should of course listen to our users".

If the decision should be made by the KDE SIG members, please proceed, I think 6 vs 1 is a good shot, even if this 1 is Kevin Kofler.
If, like Kevin said, we listen to our users, please make a public poll, e.g. on Fedora page on Google+, to see what the users want.

You can provide a better experience to Fedora KDE users, please do.

Mustafa Muhammad