I don't get it why they ask for money from people who want to learn their platform. They should be happy more people want to develop for them and charge for actual API usage instead above the free quota.

You can do pretty much everything with free membership: free tools etc. If you want to sell stuff in the App Store, then you have to pay.

I don't want to sell anything in the App Store, I just want to display an Apple Mapkit JS Map on my website, but apparently I need a paid developer account for this too, which makes no sense.