Inconsistencies in removing inline styles (or text) with backspace key

[Jakub Ś]

Steps to reproduce

1. Paste below code into source mode and switch to wysiwyg

   <p><span style="color:#0000FF"><span style="font-size:20px">abc</span></span></p>
   
   <p><span style="color:#0000FF"><span style="font-size:20px">abc</span></span></p>
   

2. Place cursor behind second 'abc' and press backspace 3 times to remove 'abc' from second line.

Results:
FF - You can't remove inline style that way (at least the first time). Element's path is still showing body span span. Even pressing Delete after 3xBackspace doesn't remove inline style. There is also one weird issue (reproducible from CKE 3.5.1) where you can remove inline style. Please see FF video.

Blink - Elements path is showing body p but if you start typing you are getting styled text and elements path shows body p font span. Just like in Firefox there is a case where you can remove inline style. Please see #13820.

IE11 - Elements path is showing body p but if you start typing you are getting styled text and elements path shows body p font.

IE8-IE10 - it is not possible to remove inline style that way. Element path will always show body p span span and thext is always styled.

Expected result

This is a very good question and I'm personally not sure what the proper approach here is. Should users be able to delete text with styles that way or should they be allowed to delete just text?

The first option will require assigning inline styles once more. The second option seems more common but to remove inline styles users would have to use toolbar or styles shortcuts.

MS Word doesn't allow removing inline style using backspace. You have to use toolbar to undo them. This might be a way to go - such approach is most intuitive and most user frienfdly IMHO