I suspect someone has a product they are trying to promote. I cannot imagine this making any sense at all.

Spam is not as big a problem these days. We have learned to filter it out in both technical and non-technical ways.

The worse problem is people who CC all kinds of people wih emails that are only vaguely related to that person's job, and 6 months later managers expect everyone who got copied to remember every line written in the thing. It is worse than the mass distribution of memos because it is so easy to do.