Motivation's always been tough for me while I wrote in the past in general. I often got unmotivated to write new articles as a copywriter, and that problem was omnipresent until I stopped. I can't give you a lot of advice in this area as a result of this, but I suggest just simply doing something else.
This Reddit thread deals with that topic a bit, but in the end fighting a lack of motivation is unique to each person.
As for whether or not writing is a necessary skill in crypto, I don't think it is. Reading and having a good comprehension on what's going on at any particular time in the world of crypto is a much more important skill that many people haven't fully mastered.
I think the "creative industry" is often underrated - writing, making music... artists will always struggle to put monetary value to their work, mainly because businesses still don't want to pay for quality - or there is a lack of perceived value for quality. Just like with art and music, writing, however subjective quality may be, is reduced to formulaic content that has proven success and can be learnt. Average writing is cheap and easily available, so there is that to contend with as part of motivation.
Crypto and blockchain to me falls under technical writing, even in marketing contexts... but as I mentioned above, few have the creativity and technical understanding to dare attempt blockchain/Bitcoin/crypto fiction.
You're right though. Contemporary knowledge of what's relevant and interesting, with insight from the different segments of the "Bitcoin community", should probably be a prerequisite for anyone wanting to try writing a book on crypto or blockchain.
