Lets make a few things clear. Systemd does not endorse CA or CLA.
CLA is irrelevant if the code is under the LGPL and GPL. It is only relevant if you want your code to be a part of the official Qt distribution, which is not relevant here.
You are free to fork the LGPL version to your heart's content. The only difference is that it won't kill the Qt project like it almost killed udev. So it is the exact opposite of walled garden, because you could continue to use Qt without systemd. Unlike udev.
Qt is licensed under QPL, GPL and LGPL, it can't be a walled garden and anyone can use Qt, study it, modify it, adapt it, distribute it, etc., even if other people don't do the same.
It isn't a "shit" . Qt has quality. For example, it's used in:
- Autodesk Maya 
- VLC media player 
- Mathematica 
- the European Space Agency 
- DreamWorks 
- HP 
- The Foundry's Nuke 
- Lucasfilm 
- Panasonic 
- Philips 
- Samsung 
- Siemens 
- Volvo 
- Walt Disney Animation Studios
- RIM (Research In Motion) 
- Google Earth, Perforce Client, Qt Creator, Adobe Elements, Swipe Nokia N9 UI, etc.
Systemd is not the right place for CA/CLA, several companies has a policy of reluctance towards signing such deals(RH included) and Debian recognizes CA/CLA as harm done to developers. So now now PLEASE SHUT THE FUCK UP about relevancy.
Qt is licensed under QPL, GPL and LGPL, it can't be a walled garden and anyone can use Qt, study it, modify it, adapt it, distribute it, etc.
Off course it is a walled garden! It adds unnecessary burdens to free software developers and excludes some as well. Oh yeah and it is just downright RUDE to demand free software hackers to give avay rights. Whats next?