I knew it they were doing it. So who is to blame hier the poor developers or the companies?

Apple issued a kind of apology citing improved user experience (reduced processor usage meant less chance of a critical shutdown) and has now offered battery replacements. So at least the company is acknowledging it, I guess?

Agreed. However, I can understand it from their perspective. Majority of their user base is not tech savvy. Implementing as default something which prevents spontaneous shutdowns at the cost of performance is the better option when the majority probably won’t notice the performance difference.