That was my interpretation too; though, I can definitely see how others would interpret it differently.
I've also seen a lot of people say this was their first jam so I think it's fair to assume many just weren't sure yet what they could handle in that timeframe and gravitated towards the more technical challenges, if any. Single-pack seems difficult at first, but some of the packs like the Kenney Space Kit and Kay Platformer kit practically have an entire game in their preview images already so I can see why people would be more drawn to it. Similarly, I can see mouse-only being challenging for a ton of genres but I noticed lots of people uploaded more management-heavy games which aren't as hard to design around not having keyboard/controller inputs (I also wonder if people were more drawn to that genre partially because many of the Kenney preview images look like management/RTS games).