Indeed they aren't. However, everyone is entitled to their own opinions. Those who saw DX:IW as a travesty would much rather not have their memories of the series be tarnished by its existence.
I don't know about you, but DX is my favorite game of all time. DX:IW didn't make me like the original any less, despite all its flaws. If it makes you like the original less, then frankly you need to think more rationally.