The reason is that these users choose to have no profile pic. Why are you trying to single them out and "take action"? Also,why did you call this project "Stop Da Invasion"? These Scratchers aren't invading, in my opinion, they're just harmless kids who want to play games, comment on them, and follow the Scratchers who made them. I'm not sure why you're trying to make this a serious issue.
Again, the comment above is not trying to be mean, it's just stating a fact.
Also, I went to the studio you linked, and I agree with @TamagotchiFan234 . Most are school accounts, and Scratch was originally made by the MIT (Massachusetts Institute of Technology) Media Lab. It's meant for school. Coding was what I learned in Media/Library class. You learn this stuff there. Scratch just makes it easy so you don't have to type in all the code.
I am ranting on @-Pixelise- 's studio and project about Scratchers with no profile pic. Rant is above (and edited) and also commented on the project about it (said project is not in the studio)
The "you" mentioned in the 'instructions' area is me referring to pixelise
Shoutout to @TamagotchiFan234 for saying (in the studio) that the accounts are for school and not an "invasion"