I agree that the scribus.net site doesn't look as visually appealing as those other sites but it's way better than what it looked like before it had a revamp a while ago.
I think the aim was that the site as it currently stands would be the start of something but it seems to have been left behind. For example, this page https://www.scribus.net/category/upcoming-events/
is essentially blank. Even if there are no up-coming events I think it would be nice if it - at least - told people about things happening in Scribus, e.g. IndigoDock, RTL language support etc. If people can see that Scribus is being regularly updated they are more likely to want to give it a try. A lot of people don't bother trying software if it hasn't been updated for a while because they assume that, if no-one is updating it then, there will be no support if it goes wrong. (Has the main developer just left it to die while they get on with something more interesting?)
It would also certainly help potential users if they could see more images of Scribus in action and/or what it can produce. There's a "Made with Scribus" page but I think the site needs to be more up-front showing what Scribus can help people to make. Without wishing to cause offence, the newsletter, book cover and installation guide on that page look very nice but when you look at the kind of images on the other product sites they look a bit "tame". And I mean "tame" from the sense that they aren't dynamic or fun or interest-grabbing. I'll say again, they look nice, there's absolutely nothing wrong with them, but they just don't grab the attention of potential users.
For instance, compare the type of images currently shown on the home pages:
* Blender - Cyborg, cityscape, some kind of Space Station?
* Krita - Manga-style characters, a dragon
* GIMP - A dragon (again) and a woman
* Synfig - More manga-style action characters
* Scribus - Some blokes sitting in what looks like an airport lounge and a printing press
I've cherry-picked the images for effect but I think the idea I'm trying to get over is plain. I know Scribus has got a "no-nonsense professional getting the job done" air about it but so do the other applications mentioned. What the others do though is say "we're doing it professionally, but we can also have fun while doing it". The Scribus website needs to say this too.
Personally I too like the Blender website best out of the ones mentioned. It catches the eye and looks great. Would the Blender Foundation allow the Scribus team to copy and modify their site code perhaps? I don't think it would take much time to make a Scribus version of it. (If I could get a copy of the original resources I could probably even knock something up myself without too much trouble.)
I realise that maintaining the website takes time and effort but once it's set-up there shouldn't really be much work to do other than updating text when things happen and changing some images every now and then to keep it fresh. How often does something happen in the Scribus Universe that needs to be reported? Every few months? Not much maintenance there.
Anyway, long story short, I agree. The website is perfectly nice as it is, but it could be more engaging.