..... snip ........I must believe that you (sic) FE was a fool, an UNSAFE fool. ........ snip ..........and, in any case, the Captain is always responsible...
I'm going to guess that you know nothing about flying airliners which require flight engineers (or first officers for that matter). Actually, based on your statement, I would assume you don't even have a drivers license. Nearly all mechanical equipment, including your tropical drink blender, has a set of operating parameters. The "book" always addresses what is safe and what is not safe. Airplanes, like blenders, have operating parameters too.
In a nutshell, after something like a high speed abort is safely under control, the next job of the F/E, F/O is to look in the performance manual and enter a chart with the appropriate data; i.e. speed, weight, etc.
Then, his/her duty is to advise the Captain about what the chart says. The answer might be that the energy absorbed by the braking system makes a subsequent take off unsafe. Or, it might be that the chart says a take off would be safe, perhaps with a period of time of flying with the gear down.
In any event, lying to the Captain is usually considered a serious breach of duty. If the chart says a take off is safe, the F/E is duty bound to say so and that in no way makes him a fool.
Naturally, the Captain is the one faced with deciding what to do and will be the person held responsible. And, according to the OP, that's what happened.
I was an F/E for a while before working my up to International Wide Body Captain. I'm certainly glad I never had to fly with anyone holding your (frankly nutty sounding) point of view about who is a fool and who isn't.