I don't think straight pylons look good, but I do think they're a signature feature of the TOS version. It's what lets you tell the difference between it and the refit at a hundred paces (even the JJPrise kept the straight pylons). Still, my take's always been that my initial reaction wouldn't have been "What the hell do they think they're doing?" if they either squished the ship down to make it sleeker, or swept back the pylons, but not both. A very slight sweep might also make the ship look better without disrupting it's TOS-ness (like, keep the taper, but have the front edge near vertical and the back edge more angled).