No one wants to switch to some unknown tech with an unknown development team.
Adopted and used first by darkweb pot dealers, like Bitcoin was.
Price supressed by government and banking hostility, like Bitcoin was.
I remember a scare some years back around a Monero developer that turned out to be a nothingburger, but it goes to show how important it is that the core development team is trustworthy, or at least sticks to their beliefs and don't capitulate to third-parties (whether public or private in nature).
Monero is the one coin I can confidently say I trust the core developers on, it's had a strong history of making the right decisions where it counts in my opinion (breaking ASICs w/the monero-classic situation, making the official client default to downloading the entire chain, etc)
https://gist.github.com/kayabaNerve/b754e9ed9fa4cc2c607f38a8...
After seeing this and their weak attempts at making a CPU-based PoW, I don't have any confidence in dero or its developers.