The use of this filter mesh thingy type cup is a valiant attempt to offer something vaguely respectable within the obvious limitations of a packed aircraft cabin. And I certainly don't blame BA for trying.
Monarch have been using the very same style of cup for a while now. I generally buy a coffee from them, as a just about satisfactory accompaniment to my favoured (prepared-at-home) smoked salmon + cream cheese bagel, which I bring on board ; a combination which works rather well.
I think if one sets expectations too high, there is the inevitable prospect of disappointment where these sort of coffees are concerned. Let's be honest .... this is never going to come close to the standard of production by an experienced Melbourne barista !