I don't necessarily blame the devs. Some actually tried to do their best to keep their projects alive but the space was full of get rich quick millennial so they had no patience to wait for projects to mature. Actually, what I have observed in crypto is that investors do kill projects at a faster rate more than the devs/owners.
You cannot blame the investors for them, they will always do the pressure game because they want to have their ROI at the earliest possible time.
Devs should not work by their emotion but by their mind, they are expected to be qualified enough to develop the project and that includes accepting the pressure, therefore they need to make a good plan for the project to survive even in tough times, if some investors will leave, new ones might come if they see that the team are capable and the project has potential to grow, remember that IEO and ICO are mostly start up projects, so it will take time to see its real value.