2) The assumption was made, by all the guys including him, that because he was a Nice Guy, I was obligated to place that above any of his other qualities and to date him for it, regardless of whether or not we were otherwise compatible.
3) My feelings or desires did not seem to matter nor enter into the equation; he liked me, ergo, I must go out with him-- because who in her right mind would pass up a chance to date such a Nice Guy?
4) When his feelings were not returned, even with a rejection delivered as gently as possible out of consideration for those feelings, he and the other guys turned on me. All my good stuff turned to bad stuff and I was to be reviled.
There are a lot of Nice Guys out there, and they are incredibly insidious, because on the surface they SEEM so sweet, so misunderstood, so very different from the boorish asshole who cheated on you or told you that those pants do, indeed, make your ass look fat. But in the end, they turn out to be using their "niceness" as an excuse to hide behind, much like medieval aristocracy used cloying perfumes to cover up the ass-stank of their unwashed bodies.
The guys I have met and known who could legitimately be called Nice Guys were, for one thing, almost invariably bitter. Either they have never gotten over being picked on in junior high/rejected by the popular girls in school, or they haven't gotten laid in a long time, or they've gotten dumped sometime in the last few years and are still licking their wounds. Whatever it is, they have a huge chip on their shoulders about it, and in their eyes the women of the world owe them for it. They don't usually verbalize it, but oh how the resentment seethes.
They tend to befriend women in order to date them. Nice Guys don't usually just ask a woman out and at least make a pretext of friendship to use as a springboard. This is where they can get confused with actual nice guys, who tend to also befriend women before dating them, but the difference is that the genuine nice guy appreciates women as human beings and enters into friendships mostly for their own sake rather than working them as an angle. The Nice Guy, on the other hand, sees women mostly in sexual terms (although he will deny it or call it "romantic terms") but doesn't have a lot of success with the direct approach, so instead he puts on a charming, harmless face in order to befriend women with the expectation that she will reward his niceness and friendship with sex. It can be a subtle difference, but there are clues-- the Nice Guy tends to come on pretty strong as a friend, and often makes "joking" sexual comments that can be dismissed as not intended seriously if the woman doesn't respond to the come-on implied in it. He will hang his belief that you would make great friends on the smallest of compatibilities-- for example a shared interest in a band, which he makes an awful lot of hay out of. He may talk a lot about how victimized he's been by cruel ex-girlfriends in a ploy for sympathy.