Older versions of the PS3 support PS2 games. They dropped support around the time the Slim came out.
Congrats Sony, you thought you'd force your customers to repurchase their favorite games didn't you? Instead you made enemies of an upcoming generation of gamers.
If only they could have heard the tears of the small children on Christmas morning upon finding out that they would not, in fact, be able to use the dance pad and the older Dance Dance Revolution which had the actual anime songs that they had saved their allowance to buy and they would only be able to dance to Lady Gaga instead...
(that's only slightly an exaggeration)
If you really want to play PS2 games, buy a used PS2 on Craigslist for a fraction of the cost of a PS3. Heck, you can still get them new.
Then they ought to stop selling it as a "PlayStation 3" once it no longer performs the functions of a "PlayStation 3". Call it a "Playstation 3--" or something.
Product model names invoke the very definition of what the product is and does, particularly when the name includes a number. They aren't just attractive words to be chosen by Marketing, even when it was the same company that made the initial definition of the feature set in the first place.
Like I said, it wasn't particularly frustrating or surprising to me to find this out after I bought it, but only because my expectations of a Sony product were so low to begin with. I would have been shocked if this had been Google though.