yeah. it's just lazy writing to have your protagonists at all the important historical events you ever wanted to write about, without changing shows
doctor who for example isn't perfect, but they make it very clear that most of the events they visit are "fixed events", so nothing changes
it's an arbitrary rule, but it…

I don't know if I can get over the fact that they A) seem to be in a hurry to chase after TIME TRAVELERS or B) that it's possible to chase after time travelers at all
it's a fundamental flaw that many of these slapped together time travel things have