Chrono Cross is one of those games that people either love or hate. There doesn't seem to be a middle ground. That it is a side story I believe is partly to blame. People wanted a direct sequel and when they didn't get it I think it soured them from the start. Going in with an open mind definitely helps to better enjoy this game. As for Xenogears, I think some of the developers time on Chrono Trigger influenced the game but I don't think it was ever intended as a sequel. People read too much into Lucca at the beginning of it.
Since the fusion of Squaresoft with Enix i do not really look for a sequel of the Chrono series. Will not the same without the old Squaresoft crew.
I don't mind people hating it if they truly find it to be a boring game, but when people instantly hate it when they realize how little it has to offer them in terms of a "sequel" to Chrono Trigger.... Well... I hate those people.
My main memory of Chrono Cross is of how bland the narrative was. There are so many characters in that game and they come and go so quickly that you never get to care about most of them. I'm pretty sure I remember them swapping lines too at points, like they were just repeating generic lines of dialogue. Basically, there's a reason books don't tend to have 100 unique characters - you can't keep up and don't get get a chance to connect with them. A lot of the character designs were pretty silly, too. A bit too far for me even by JRPG standards. And while I'm having a moan, I don't like the soundtrack anything like as much as Trigger's. Some of it is downright obnoxious.