When Samsung announced the Galaxy S21, it surprised the world with its choice of materials. A plastic back on a flagship shouldn't be allowed, right? Or should it? Samsung does not want to have that discussion all over again and makes sure that the entire S22 series gets a glass back.
We too joined the bashing of the S21. Plastic on a €800 phone, who on earth thought that would be a good idea?! In reality, it wasn't all that bad. The matte finish felt pretty premium, didn't smudge like glass does and doesn't shatter into a thousand pieces when you drop it. On top of that, it's lighter and feels warmer in the winter months than say metal.
The S21+ and S21 Ultra did get a glass back, by the way, and it looks like that will soon happen for the entry-level S22 as well. At least if we are to believe the rumor of Ice Universe. He often reports about unannounced phones in advance.
More differentiation
At the time it was assumed that Samsung opted for plastic to keep costs down. The entry-level Galaxy S21 did indeed had a lower entry price than its predecessors. However, that price drop also applied to the glass S21+ so maybe that wasn't the real reason.
It's not inconceivable that Samsung wants to make more of a difference between the premium Galaxy S22 and the lower cost S21 FE which will most likely continue to use plastic. Which way Samsung is going to go will become clear during the Unpacked Event which has yet to be announced.