It's an entire species. The idea that they only had kids the once and then they sent them all away is just obtuse. No sentient race could survive with a reproductive strategy like that.
The Horta have children only every 50,000
years, after which the entire species, save for one, dies
. Is that obtuse, Sci
? Are the Horta stupid for reproducing like that? Are the Horta not worthy of preservation because they don't reproduce like humanoids? Should only humanoid species be safe from genocide?
The Founders are no more humanoid than the Horta. The Founders have much longer lifespans than humanoids, maybe even nearly biologically immortal. Certainly they can live for multiple centuries easily. With that kind of lifespan, why should we assume they have offspring on a regular basis like humanoids? Can you imagine a biologically immortal species that insists on reproducing like humans? They'd fill the entire galaxy eventually, faster than you'd think.
It seems to me you assume the Founders are exactly humanoid so that you can be offended by the attempted genocide against them.