Naturally, as it is with any ethnicity, White people’s attitudes and opinions aren’t uniform, and can’t be generalised. Then again, statements beginning like this are based on the idea that Black people, and other minorities groups can’t say those particular things. In addition, it is important to clarify the fact that these types of assertions are not necessarily accusations of racism; they satirically reveal ignorant and/or insensitive behaviours and stereotypes. Therefore, answering “Not all White people are racist” is very much an off-topic response.
However, even if it is true that you don’t have to be racist to make such inconsiderate remarks; racists undoubtedly do hold such views. And, whether we like it or not, it is important to acknowledge that an alarmingly noticeable amount of Caucasians are racist. Remarks beginning in “Dear White people” are thus not based on the definite assumption that White people are racist, but rather on the substantial probability that White people could be racist. Moreover, these types of comments serve in essence as a way of checking, of verifying one’s attitude. I.e, if you don’t engage in such behaviour, good for you: you can ignore the underlying seriousness of such remarks and enjoy the humour of it all.
Hypothetically, saying “Dear politicians, stop being so corrupt”, shouldn’t conjure up incensed politicians complaining that “Not all politicians are corrupt”. The fact this that, as corruption is an issue with politicians, racism is an issue with Caucasians; whether or not these issues concern the majority of politicians, or the majority of White people.
As for why Whites can’t say “Dear Black people” without being called racist; this goes back to the most fundamental and yet polarising issue as it pertains to racism: that racism isn’t reciprocal. Why can Black people to Whites what White people can’t say to Blacks? The answer is trivial: races are biologically equal; but social experiences between ethnicities differ. This is especially apparent in this particular instance; as the only reason why Caucasians can’t point out racially insensitive remarks uttered by Black people is that Blacks live in a world where Whites dominate politics, finance, beauty standards, the media and most other facets of society* so much that Blacks know and understand White people too well: it becomes harder for them to have ignorant and racially insensitive opinions of Caucasians. So I don’t think you’d have many ideas for a series called “Dear Black People”, unless you do indeed insert racist viewpoints into it – which is why you’d be called a racist – or state falsehoods throughout. Lack of subject matter, I’m afraid.
What’s comically puzzling to me is the fact that, at a time where people complain about minorities getting “triggered” by “politically incorrect” comments, the same people will be outraged when the comedic arrow changes direction.
*Relax, I’m not blaming White people for that, so you can stop clenching your firsts now. I’m simply stating a fact; without trying to assess its causes.