People just think your not trying to straighten your back hard enough because your being a pussy. Maybe thats the case, but I personally know that it could also just be because you have terrible flexibility and/or shorter arms.
If you are truly trying as hard as you can to straighten you back and you are having difficulty with flexibility, do RDL's. Make sure to straighten your entire back at the top and only go as far down as you can until going any further will make you bend your lower or upper back. 6 months ago this was literally only till my knees! Do this multiple times a week adding weight to it like any other exercise and eventually you will be stretched out. I can now get into the deadlift position and straighten my back, but JUST BARELY. So it will not be a short road, but it is one that you need to take if you will ever be flexible enough. I haven't heard or seen anyone post a better way yet. I know Rip mentioned ART (active release therapy), but I have not done it so I cannot speak to its effectiveness.
I saw an SSC coach recently and he agreed that my best bet at the current time is still doing a set or two of RDL's as warmup to my deadlifting. Otherwise I can't get into the position without rounding my back.