I think the main problem is that the open source model of software development doesn't really work when it comes to visual or interaction design. We've all heard that phrase 'design by commitee' but that's what you get when everyone wants a say in the way the UI works.
I can understand why this happens even though the outcome is often an unfriendly UI. Imagine you're a developer who's spent time and effort contributing to an open source project. Naturally you'll have an opinion on the UX and what suits your preferences. Everyone else using or contributing will also have a strong opinion. The moment you try and delgate visual and interaction design to a small, dedicated team is the moment the whole project generates enormous resentment from the "community".
Plus, any attempt to (sincerely) improve or simplify an interface will always be met at some point with the charge of "dumbing down".
Open source and design have never had a good relationship. I wish it were otherwise, but I don't know how it could be made better.
I was talking in general about Open Source and design not about Plasma. But since you ask, here are some small things I noticed in the video
- Mismatched visual styles: when you tap the phone icon, you get a bar of three icons. Two are simple line icons (History and Contacts), the third is a detailed picture of a keyboard to denote keypad. A minor thing and easily fixed.
- Interface inconsistencies: I noticed that a large red X is used for closing a screen (which I like over the sometimes unclear Back button behaviour you get in Android). But at 3:16 in the video the Wallpaper screen has a 'close' button (with X) and below that in the tab bar is the larger red X for closing too. So you have two close functions on the same screen. You see the same duplication on the date and Time screen at 3:41. By the way, I think the way Windows Phone lets you change date and time is much nicer. It's a similar spinner approach to Plasma but less cluttered. Here's a video of it in action: https://youtu.be/kIsWgCX7qtE?t=54s
Also, the commands 'close', 'cancel' and 'delete' all tend to use the same X icon in many UIs so if there is no label for X, then it's meaning (and behaviour) should be consistent across the OS.
- Weather app: there is a 'hamburger' menu on the left and another slimmer hamburger menu on the right. They feel too similar visually. Presumably, the right-hand menu is equivalent to the overflow menu you find on Android. But are two menus needed here? Could they not all sit in one menu?
Obviously, this is a beta and these are relatively minor points. I can see some influence from Android, which is fine - there's no doubt that Google, Microsoft and Apple all study and are influenced by each others work. I just hope the OS stands up well as a unique UI rather than just a clone of bits from other OSes.
Overall, it looks quite polished for a version 1.0 and I hope the project succeeds. I would love to see an open source project take the lead in design/UX over existing projects.
Removing features will be met with criticism, but a lot of KDE software is still using UIs made in 2007. A much more modern approach would be minimalistic defaults with a lot of under the hood configurability (which Qt and KDE are really good at - you can add panels, frames, etc to tons of apps seamlessly and put buttons everywhere if you want) which includes settings, where you have the default settings panels be the known most popular / important options (default download location, font size, etc) and you have an advanced toggle to get the traditional KDE overkill settings panel.
I can understand why this happens even though the outcome is often an unfriendly UI. Imagine you're a developer who's spent time and effort contributing to an open source project. Naturally you'll have an opinion on the UX and what suits your preferences. Everyone else using or contributing will also have a strong opinion. The moment you try and delgate visual and interaction design to a small, dedicated team is the moment the whole project generates enormous resentment from the "community".
Plus, any attempt to (sincerely) improve or simplify an interface will always be met at some point with the charge of "dumbing down".
Open source and design have never had a good relationship. I wish it were otherwise, but I don't know how it could be made better.