The sad thing is that no one can use the hole on the MG "market" (only in the negative sense - scam).I think most people are waiting for someone to make a good game. Lots of genres were made trendy again cause a good dev made an awesome game (Stardew valley, Fear and Hunger etc.). Lots of people that saw MGI in 2015 as the next big hit but sadly here we are. So hopefully some new dev will make it a reality.
MG games fall into the abyss very quickly. The worst thing is that everyone uses the name Monster Girl ... Something, Anything, Nothing, Fucking with the hope of feeding on MGI. But since everyone suffers from syndrome named "Redamz", they prefer not to invest in it. Circle of madness.
What do you say about Monster Girl Ranger?
It looks nice, but support almost zero, but Dev is still active.
I also liked Monster Girl Assistant (2 Demos - 2 Girls and Dead Project). 95% MGI clone, maybe a little more advanced, improved. And of course Monster Girls Hotel. Quite funny scenes and story but developers closed the shop quite quickly (Prologue + 1 Chapter). But it's worth trying.