I really think it is the weather. I have been gardening for nearly 20 years now mainly with 2 brands, first with Bolster and the last few years with Bingenheim Saatgut: both very high germination rate. This year it is a mess. I still have to get good cucumbers, broccoli, cauliflowers.. and I am very lucky with the active 'exchange habit' between the plot owners. Because of my neighbors I have green beans, black beans, several pumpkins, part of the chillies and tomatoes.. I am even buying plants this year.
The funny thing is: it seems every one has a different succes. My eggplants and kale sort of exploded, so now I have about 30 of them.