The problem is that nobody trusts Oracle. Have a look at what happened to Google. Their code didn't even originate from Oracle and they still got sued for made-up, bullshit reasons.
It of course sucks for those who invested their time in hacking the Oracle stack, but I think many people these days outside the Oracle bubble see Oracle as a dead-end.
Most people don't have a war chest full of money to hire the best lawyers like Google to protect them against baseless lawsuits.
Anyway, even from a technical point of view, things like Graal and Truffle are terrible workarounds and I prefer just fixing the things which are broken in the first place. Seeing that this will never happen at Oracle, I'll just work on code were the maintainer/owners are not so openly hostile.