Have you ever maintained a product popular enough that lots of people try to hack into and abuse? If yes, you should understand the reasons for protective measures like this.
Why not allow users to decide themselves?
This functionality is enabled by default. That`s why I`m asking - why don't ask the user first?
Upd: please be civil, this is a discussion and not a competition.
As for default, that's a different question unrelated to user freedom. Unfortunately in Windows, DLL injection is very often abused for no good reason. Imagine a simple, non-technical user getting asked about permitting mouse driver DLL.. what would user think? With only information being DLL name/description, they might think that mouse will not work without it and permit it (see https://news.ycombinator.com/item?id=36681873 for real reason). And once firefox starts crashing, will they know how to disable it?
No, it is much safer to disable it all by default. And if a powrer user needs a specific DLL, they can enable it. As a bonus, they will learn where the dialog is, so they can disable it back once the crashes start.