throwaway9w4

Is there any documentation of the api, so that someone can call it directly without going through the sdk?

You may be right, but this is just one example

Also, backend people can be arrogant as well, but it seems that for some reason new ideas tend to be picked up quicker in frontend, which unfortunately results in bad ideas spreading fast too.

I agree with you

It reminds me of an online store in the beginning of 2000s

To buy a product, you had to drag&drop the product image over the shopping basket icon. It took me quite a while to figure that out, and I bet they lost a lot of customers.

[Edit: I acknowledge that a PM or manager may have forced the developer to do this, but it's just one example of many]

Sometimes the developers have to take the blame, instead of blaming "stupid" users. Some take that attitude to frameworks as well. If the users complain, they haven't understood how to use it correctly. Just look at the "how to make a todos in 5min" video on YouTube to be convinced of its beauty