. . . in a organization of any significant size, it's generally a bad idea for developers to make unilateral decisions about how the product should be changed.
Yes, you are absolutely correct. Now, if only Marketing or the business units would get their heads out of the collective asses long enough to actually provide usable direction to us developers, we could all go home and have milk and cookies before naptime.
I have worked at 9 different places in the past 7 years. At 5 of them, developers wrote specifications. At 2 of them, developers co-wrote specifications. So, in less than a quarter of the places I have worked at, developers received usable specs.
I've been lucky.