I think a lot of factors are involved here - DE features strongly as they have a strong culture of listening to "cable radio" (they had (analogue) radio stations via the telephone wire since the 1930s!) and tech/electronics hobbies (similar to NL). There is also less of a gender gap when it comes to tech-related hobbies than the UK or some Southern European nations (I notice this as well amongst young women from Eastern Europe and many who are of Asian ancestry)
you are similar in many ways to my younger sister (same age as yourself) - she has a day job in marketing and web design but is heavily involved in the local music scene, sings and plays guitar (her favourite music is country and western/folk which we grew up with, although our parents being from Malaysia! - this may be why I've got to quite like listening to piratenhits
)
Whether or not you intended it, your station appears to be targeted at a certain kind of intelligent, confident European young woman (aged around 18-45) who understands English as either a first or second language, works in a skilled/professional job, is socially liberal in her views but has concerns about some modern pop music and its content (especially attitudes to girls/women and other aggressive lyrics).
However these young women are now increasingly likely to be mothers and may spend weekends with children - if they only own one device capable of listening to an internet station such as a laptop, the children may be using it, supervised by their mother? they may even be embarrassed about their kids learning about what their mum got up to in the 80s/90s
Also there has recently been particularly good weather across Europe, so may have spent their weekend attending festivals with friends and family, riding their bikes etc (one of my favourite songs from NL is in the Drents dialect and is about these friends who went on a "short" bike ride around Groningen just around autumn, this took them 80km including across the border to Germany and back !)
Perhaps now the weather has changed, things will improve? winter is often a time for starting "indoor" hobby projects where folk are more likely to want to listen to music in the background, and be close to a good net connection?
I was thinking today that the young women at the housing co-operative would particularly enjoy listening to your station (and also reading your website). I will send them the link, but I know that only 2 out of the 5 there would be able to get a good wifi signal, not all of them have smartphones, and it might be some time before I can get there and install a better router ...