If it's that much of an issue, then they shouldn't have bothered to put it on in a first place. If they can put on a show that they own entirely that brings in the same numbers, then shouldn't they have just put that on in the first place.
The business is not as simplistic as that, not something you can reduce to a single yes-or-no parameter. There are many different factors to be weighed when assessing whether a show is worth buying. As I already said, not owning the show can make it comparatively
harder for a network to profit from it, but it still
can profit from it if it gets good enough ratings. Just because something is less of a sure thing, that doesn't mean it isn't worth trying at all. If networks thought that way, they wouldn't have enough shows to fill the schedule.
Every show is a risk. There's never an absolute certainty that a show will be profitable. This was
somewhat more of a risk for Syfy than
Killjoys was, but it wasn't that huge a difference. After all, they were able to keep both shows on the air for three whole years, which, as I've shown, is longer than the average run of a Syfy/SciFi original show. Both shows were relatively successful, so obviously it was worthwhile for Syfy to buy them both. It's just that DM was marginally less successful, so they couldn't sustain it for quite as long.