Non-geeks do not use additional search syntax compared to the number using the nice obvious and clickable "Images" or "videos" tab.
I disagree, and I think we can see the counter-example very clearly with altavista.
You could go to altavista and type in "dumb" search queries, just like google.
But simultaneously, with no change at all in the UI and no constraints imposed on the "dumb" users, you could also type in very sophisticated boolean searches like:
linux grep ("regular expression" and "regex")
and get very precise and sophisticated search results.
I miss this every single day
That's what I was trying to get at :)
For the time I'd also argue that their "on-boarding" was excellent: a textbox and two buttons, you can't get simpler :)
The 2015 equivalent would be adding animated instructions in a pencil typeface on the search box and buttons. The demographics and expectations are different now.
A lesser example: half the time I want to use a menu-item in OSX now, I find it by going to the Help menu and typing something in the fuzzy-match box. I'm not sure why this hasn't been made the primary OSX menu interface.
Lycos
The problem is on-boarding - once the user learns to ask for computer a question then the text (or voice) interface has the potential to be on a completely different level than a graphical interface.
Just imagine - instead of searching through a dozen menus for an option you just ask.
Hell, that's how most people work with Microsoft Office now - fumble around trying to find out where they've hidden the option. Fail. Open Google and type "how to change signatures in Outlook 20XX".
Slack solve that brilliantly - their on-boarding is well designed - the way it gradually introduces features and reinforces concepts is excellent. It reminds me of modern videogames in design.