There's a massive sightline at 1. Not at 1 itself, but just around that corner. It's also extremely open, so it's not even like the Tunnel in Badwater or the section inside the second barn (the one which houses 2) in Barnblitz, so you're exposed from a big height pretty much all the time, which makes it harder to try and take down the guy. 1 was fun in general, just has that minor problem.
As for 3, there's a few main problems with it - the respawn times when 2 is captured but 3 is not are way too long, and Red can barely set up a good defense in that meantime, or just set up a defense in general, seeing as there's a massive height disadvantage for the reds. A little bit more of time just leading the bomb around could put the reds in a slightly more defensible position, but the height advantage from up that hill to both sides is actually pretty powerful.
Anyway, just my two cents.