Because the point of trying to intimidate is trying to get them gone, likely because of dislike of what they are doing. Increasing their follower count exposes them to more people and thereby is a complete backfire in terms of minimizing their reach.
Also increasing their support will make them feel less vulnerable or scared, and less likely to back down.
The entire point of doxxing LoTT was to try and intimidate her until she stopped.
Clearly, that backfired as she's gotten more followers than ever.
So, what does the number of followers have to do with the effectiveness of intimidating the account owner?
Because the point of trying to intimidate is trying to get them gone, likely because of dislike of what they are doing. Increasing their follower count exposes them to more people and thereby is a complete backfire in terms of minimizing their reach.
Also increasing their support will make them feel less vulnerable or scared, and less likely to back down.