What choice did they have? Either break compatibility, or use type erasure.
Their fundamental concern is to milk Java as much and as long as they can to drive their sales for Oracle DB and associated business products. And that makes perfect sense too, they are in business to make money anything else and they won't be doing their job properly. Don't you see what has become of Sun Microsystems? They were making awesome stuff by the day for somebody else's profits. Oracle is not going to make the same mistake again.
Java is oracle's strategic investment in using that as a leverage to drive sales else where. And looking at their segment, its mean't mostly for large corporate programmers and not hacker, start ups and alike.
I bet IBM makes sufficient contribution to COBOL still just to keep their mainframe sales alive and not because they want COBOL to be awesome enough to rule the world.
Similarly Oracle's contributions and investments to Java are going to be for driving their sales not for sake of making Java awesome.
But I downvoted you because this has almost nothing to do with ootachi's comment about the realities that the designers of generics had to cope with. You're just regurgitating the same criticisms that has been leveled against Java for years.
>>What choice did they have?
The only choice Oracle has is to invest in Java in areas that is going to help them sell their products.
That is the only choice Oracle has.
ootachi was was referring to the designers of Java generics, who were working sometime before Java 1.5 was released in 2004, long before Oracle bought Sun.