I’d like to take a moment and clear up several misconceptions here.
In my opinion, things make more sense when you really think of a VF as a single font with all the instances “growing” from it – rather than looking at an axis-based spreadsheet. This single font is the origin of your designspace, it is where all the axes meet.
- The default font does not have to be “Regular” – in the OP’s case the default would be “Compressed Thin”
- If you however want Default == Regular, you must include a Regular master. That’s not Adobe’s doing, that’s just the design of VF.
- Whatever your Default ends up being, the “basic” font info (OS/2, name, etc.) should reflect that and not necessarily “Regular”
@GeorgSeifert: There are some of those test that require that the origin master is at weight 400 and be the same as the “Regular” instance
This is not accurate. There is absolutely no necessity to insert a Regular master into your designspace, just to appease FontBakery checks.
@jkutilek: I don’t think any fontbakery check requires that there is a master at the axis default.
I don’t think there needs to be a check for that, because a VF could simply not be built without having masters at the axis defaults. The combination of axis defaults again is at the position of that origin master 
Thank you also for pointing at the backwards wording in the FontBakery test – this will be addressed – just as we’ve already already addressed the “no Bold instance” problem.