I'd say Construct 2 belongs at the top because the topic is specifically "2D Engines", were it Indie game engines overall then it could be second place to Unity since its definitely not better than Unity for 3D.
However, as someone who switched from using Clickteam products (KnP, TGF, MMF, MMF 2) and never looked back, I definitely don't see why Fusion 2.5 is as high up as it is.
However, things like this seem to be just a "who has the biggest fanbase" poll rather than a true poll of what's the best tool to use, so things like "who has a better free demo" will mean they have more fans to review it and push it right to the top.