SGU's first season wasn't stellar - that didn't help, but it was far from horrible either. I think its very fair to say that SGU season 1 was 50:50 when it came to good episodes and bad episodes. Hold that next to any of the Star Trek spinoffs, The Clone Wars, or even Stargate SG-1 and I'd say thats a better ratio of good vs bad.
Of course, taste is subjective - it didn't appeal to everyone, but on the flipside of that I was a fan of BSG, SG1, SGA, the first season of Heroes and LOST. All of which are similar shows, and all of which were financially viable enough to last more that 2 seasons. Yes, the argument could be made that SGU was nothing but a ripoff of BSG or what have you, but outside of very general things like lighting and the setting, it quickly differentiated itself, especially in its second season. Looking at it in that light, if all those similar shows could do well for themselves under similar circumstances, why didn't SGU succeed? Limited audience share? Lack of promotion? Bad scheduling?
I think the fact that other high concept shows which have become exceedingly popular such as True Blood and Breaking Bad have been aired over the summer away from heavy competition helped those become as popular as they have. Sure, they're not the same as SGU, but in their cases I do feel that airing over the summer helps them. SyFy also claim that Warehouse 13 and Eureka do well, but they also air over the summer (I guess it also helps those shows look like they cost $10 to make vs SGU's gorgeous sets).
So basically, yes, there is no accounting for taste, but when you look at other popular shows which SyFy champion as being ratings winners, and look at when they air - there is a disconnect there. If they aired Warehouse 13 at the same time as Hawaii 5-0 and Two and a half Men, i'd like to see what the ratings are for that.