Right, nothing shady about this UI pattern at all.
>"This installer may include bundled offers." makes this also very clear.
It makes nothing clear. It's purposely vague language used to disguise the fact that these "bundled offers" consist of software no person would actually chose to install on their machine.
>For anyone saying that Filezilla can't be trusted anymore due to doing this, it's still open source and you can check out and build the code yourself: https://filezilla-project.org/sourcecode.php
What would that accomplish? The issue is that the dev doesn't even know what the hell comes across the wire when you chose to install this crap. How is reading the FileZilla source helpful?
It's funny, I've been using the Internet long enough that I almost instinctively ignore such buttons and look for the actual link. The bigger and more lurid they are, the more easily I ignore them --- just like automatically scrolling past banner ads and such, I suppose it comes with experience.
Of course sometimes the "too obvious" button is the right one, but that's been a minority.