I believe this is the reasoning behind the limit:
And looking at your reasons for wanting to increase it, it seems it’s also a good way to prevent admins from doing a similar thing. 
The 100 limit is fairly arbitrary, though I think there is some scope to maybe amend this in the future. However, I’ll close this feature request off to give the space to someone who can come up with, let’s say, ‘more legitimate’ reasons…