I'm not sure how many people care. It's like finding out Pepsi owns Aquafina.

Many don't even realize Facebook is a company.

Why is that funny? Lots of businesses go to great lengths to segment their products and sometimes play them off each other (e.g. Blue Moon pretending to be a craft microbrew despite being produced by MillerCoors).

Not really any different having two jewellery stores opposite each other in a shopping mall giving you the feeling of choice. Only to discover they are owned by the same company.

I mean, it's the same company but a different product (aside from the ads which are the real product). IG has pictures that are cute or funny or cool, FB is a sordid wasteland of misinformation, bickering, and unhappiness. I'm ready for IG to devolve into another misinformation machine any day now since that seems like it is really lucrative for FB, but for now I think IG's simplicity and image focused UI filters a lot of the garbage out.

I also don't know I'm "using microchip" with my Atmel or SMSC - and I really don't care either.

You and others here probably don’t know half of the companies or brands owned by other companies or brands.