Statistically that's true because very few novels are ever animated. It's very selective.

On the other hand, LNs are being adapted left and right regardless of quality. Popularity is the usual standard, and that's not a good one.

Generalizing that LNs are bad is like saying anime is bad (you know, because trash anime are all over the place, that's fact). You just have to read the better ones to understand.

I'd actually agree with you if you're merely pushing the statistic that novels are likely to get a better adaptation than LNs. I don't agree with generalizations, especially from someone relatively unfamiliar with the medium.