>>281660578
FGO does yearly surveys on the playerbase, and according to results, 44% of the playerbase started playing because they were Fate fans already. And when asked what their first Fate-related work was, 2044 said FGO, while 1406 said they started with the VN. I can't find numbers for Kara no Kyoukai since it technically isn't a Fate-related work, but for the record, Kara no Kyoukai had two events in FGO and both of them were pretty popular. In any case, that's a pretty large piece of the pie that has played the original Nasu works. I think you underestimate just how invested in the franchise Fate fans can be.

>>281592998
The evil spirits are still very much so evil. In many events they are the cause of problem, and in interludes, you are constantly kidnapped or put in precarious situations by them. Some of these events even feature bad events where you trapped into eternal rape hell by at least 2 servants (Kama and Kiara).