You are not the only one ... Personally, I know lots of VN readers who just play only 2 or 3 heroines (sometimes even just 1) out of 5 or 6 in the VN, because those were the ones they liked xD There's no point in reading a heroine's path which you don't like, that's worse than not reading the VN 100% ... You just burn yourself out and start disliking the VN medium xD ...
I like to read most VNs and can enjoy them utill the end so I have no problem finishing all VNs fully when I start reading them ... Also, I am kind of a slow reader, so I usually take more time to read something than your a