I wonder why Apache would need to have two "more similar than different" products.

Apache accepts anything that companies donate. (They say they don't, but it's hard to find anything they've rejected.)

That's not quite the right emphasis.

Apache is happy to provide a home for any community that is willing to adhere to our governance rules and traditions. Competing projects are OK.

Projects are almost never rejected because preparing a proposal for incubation is rigorous and many projects who would be a poor fit self-select out.

Source: former VP Apache Incubator, who has both helped prepare successful proposals and privately counseled projects who decided not to come to Apache.

because people are interested in maintaining each