If you've previously edited while not logged in (or while logged in as another user), and changed your editor to wikitext mode, then your editor preference will be carried over when you create a new account. I suspect that this is how the account you were testing with ended up with wikitext editor as their preferred mode.

@Chaduvari Can you try creating a new account while using private browsing mode (https://en.wikipedia.org/wiki/Private_browsing), or after changing to the visual editor while logged out?

@matmarex You are spot on.

I have logged out from Wikipedia, converted to Visual editor, and then created a new user. When tried to edit, this time it showed me Visual editor.

But ideally, I think, the "Always give me the visual editor if possible" option should be selected for the new users.

Anyway, thanks for the support.

The newcomers should invariably get the Visual editor by default, no matter what they were doing before creating the account.

Thanks