I have added this request to the tracker:
Issue 2391 – Do not close editor on Esc key
You can vote for it there.

Couldn't agree more with the original original poster!

I'm a new user (migrated from CuteFTP) and have already lost track of the number of times I have had multiple files open, ran a search, thought I had the Search dialog box still open, hit Esc (to close dialog box) and lost the file because I didn't have any unsaved changes (yet)... Then had to navigate to the original file location again.

This isn't the behaviour in legacy apps like CuteFTP or current apps like FileZilla.

Esc is usually reserved for "Cancel" actions rather than Quit/Exit.

Generally expected Windows behaviour is that Esc closes a Dialog box, closing a file should require Ctrl+F4.

If you open a file in Notepad and hit Esc, nothing happens. If you have a Dialog box open it will close it.

https://www.quora.com/Does-the-escape-key-on-a-PC-do-anything-at-all-It-seems-to-do-didley-squat-in-every-single-application-and-situation-Ive-tried-it-in

I mean what do you expect Esc to do when you press it in editor window?

To get out of popups. Not to get out of an entire application (yes, I consider the text editor an application and not just another popup).
=m

What do you expect Esc to do?

I have been using WinSCP for years but the #1 annoyance about this program is that the text editor automatically exits completely when the Escape key is pressed. Please add an option that will suppress that functionality. It creates more work. Thanks.