Tragically, all children exposed to the DNA of Hashirami Senju had passed away after a certain amount of time, so Orochimaru presumed that the remaining test subjects would all suffer the same fate.

Orochimaru was able to successfully implant a Curse Mark about 10% of the time. The other 90% of the time resulted in the deaths of each test subject Orochimaru's bit. Throughout Naruto ...

Villains in Naruto share a similar trait across the franchise: they are tragic characters who facilitate empathy from the audience. Orochimaru isn't a tragic character, nor is he worthy of empathy.