The rating by Kryptous of a C- uses 10 factors. They explain all the things BTC has right and all the negatives.
The Weiss rating has only 4 Dynamics.
Some strong A's but lots of D's.
Pretty elaborate 10 factor system.
50 Max score BTC got 27 points for a C- or almost C Rating.
https://kryptous.com/btc-bitcoin-rating-by-kryptous/
I don't think this stuff is going to have any impact at all. Ratings are used in mainstream finance as a way of covering people's backsides (they can say, "it's not my fault that our pension fund invested, we followed the ratings").
But pension funds and institutions are not the main investors in bitcoin, it's dominated instead by private individuals, most of whom know loads more about cryptocurrency than these ratings agencies.