Fargoo,
Whilst i agree with much you said in your last post,your assumption that it is ok to run an engine at high power settings "unguarded" is not totally correct,especially within BA.
Whilst i agree with you that if you are at a remote location,(ie doing a block run on runway 23 at LHR),this is acceptable,as everyone should be secure in a van/tug etc...well away from the a/c
However do the same thing within the confines of the run up pens at the maintenance base and you immediately fall foul of both H&S rulings and the BA Quality dept as "appropriate engine guards" are provided at these locations!!
Its sad to say,but there are a few individuals i know that tend to often
"overlook/dismiss" these requirements as they are always under pressure to get the job done!! All well and good,until something tragic happens.....then see how much support you get from those above you!!