When you join two different materials they will expand and contract at different rates when exposed to different levels of humidity or temperature or pressure. This isn't abstract laboratory ideas- leaving the door open in winter will drop the temperature, someone walking in with boots caked with snow will melt and soak the materials in water, someone walking on the section of floor is suddenly putting a lot of pressure on that section. Sometimes this can be ignored. You can just slap drywall right onto wood and be reasonably confident there won't be any serious problems down the road because the two materials are similar in properties.

Tile has significantly different properties than wood. Tile means one of three things- ceramic (aka terra cotta), porcelain, or natural stone (fucking expensive). All are brittle. That means, while difficult to scratch or scuff, they cannot flex without cracking.

OSB means oriented stand board. The stuff that looks like a bunch of wood chips smashed together. It readily absorbs water, expanding and putting a lot of force on things it's in contact with as it does.

Backerboard is a cement based product installed under the tile with similar properties to tile with regards to expansion and contraction when exposed to heat, moisture and pressure.

So what I'm saying (and thank you for still reading) is that tile installed over OSB will experience a lot of stress since the two materials will expand at different rates and one will put force on the other, cracking the tile which can't bend. Laminate flooring is also a wood based product and will also cause the same problems to tile it is directly touching.

Thank you for coming to my ted talk, sorry for this being so long, recommend me for best of reddit etc.