I'll quote the last two paragraphs of the piece, which I think summarises the key problem with EPMS.
"With EPMS, teachers have been advised by school heads to do more in order to be ranked better among their colleagues. It is no exaggeration to say teachers ensure their portfolios are bulging with details of their current worth and potentials.
The question is whether teachers are losing their direction and focus, which is to teach and to do it well."
In case anybody thinks that this is really teachers' own problem, don't forget that these are the same teachers who are teaching your children. If our teachers are fixated on doing more and more projects to get a good EPMS ranking instead of focusing on teaching the students, who really suffers?
A particularly pernicious consequence is that any adverse effects will impact the less well-off disproportionately more than the well-off, if only because the latter have more options, e.g. sending their children overseas or to independent schools (who presumably are able to avoid the tyranny of EPMS).