Well, it was VERY successful in terms of being a wonderfully entertaining and meaningful show to me and the other fans who loved it, so I don't care about whatever you perceive SyFy's standards to be. It survived for four seasons and told a complete story, and I loved it all the way through.
I was also a big fan of B5, but I don't know if a remake (nuBSG style or otherwise) would really work for the show. Unlike the original BSG which doesn't really have much at all going for it, in my opinion B5 has many iconic and un-changeable components, including Katsulas and Jurasik as G'kar and Londo, "If you go to Z'ha'dum, you will die," Koenig as Bester, and I'm even even a sucker for the infinite cheese-factor of lines like "now get the hell out of our galaxy!"
I wish it were possible to tweak and change a few things about the original B5 like some acting/casting choices, some cheesy dialogue, so-called "comedy" scenes, and a few general story ideas...but overall I think B5 is great enough on its own that it won't ever really need a reboot. JMS's ego produced a great show in the end, even if it also prevented it from being an amazing show.