I do not think of aggressive as a criticism. ... Also aggressive is different to fighting or confrontational as it implies one is trying to attack the opponent .
We get into very murky waters here. Different people have different notions, but so do different peoples.
For English speakers, if you do a google search on 'aggressive' and look at images associated with it, what you will see is a whole lot of images of people being confrontational - clenched fists, jabbing fingers, shouting. Now if you imagine yourself as a trained martial artist (i.e. a pro in go terms) being the subject of this attack, you would know that you have won already. Your angry opponent has given away far too much about his intentions. So that has to be criticised as a flaw in the attacker's stance, surely?
There is a recent usage of aggressive to mean 'bold and determined', as in an 'aggressive takeover', but it would be my sense that only MBA students would see that as totally without criticism. Most of us, I think, would feel a certain unease, even if we basically admire or envy the boldness. Go people who advocate aggression are probably thinking of this meaning.
But if we extend the discussion to see how (say) the Japanese see it, it becomes even murkier. The usual words for 'aggressive', if you believe the dictionaries, would probably be 攻撃的 or 侵略的. But if you copy and paste either of these words into google images, the result will be light years away from the images you get for 'aggressive' in English. I venture to say you wouldn't even think of aggression if you just saw the Japanese word's images. Neither of these terms is at all common in go, incidentally, and when a Japanese go player wants to talk about being 'too aggressive' he will use variations on the theme of 'overplay'. Or may even occasionally borrow the English word 'aggressive' - ｱｸﾞﾚｯｼﾌﾞ - but if you images.google on that, again you won't get anything that really resembles what you get for the original 'aggressive'. You have to then start thinking whether there are even deeper cultural reasons for the differences. Is western aggression in go about being macho and having cojones? Is Japanese aggression in go about keeping attacking options open and worrying about stones of a different type?
If a Japanese go player wants to talk specifically about a 'bold and determined' attack, he will normally use phrases such as 力を発揮する。The central word there is 力 which the dictionaries tell you means 'power' or 'strength'. But again the dictionaries are misleading. It is instructive to google images for 'power' or 'strength' (in English) - you will get swelling biceps, punching fists, dumb-bells, and the like, but when you do this for 力, you will get something completely different, including scantily dressed girls and cute babies.
Part of the reason for this difference can be gleaned from how a pro talks. Take Yoda as an example, since we've mentioned his book recently. He mentions the problem that we have labelled as being 'too aggressive' and says the reason it is bad is that it indicates a mistake in one's feeling for the overall position (which, recall, is what is book is all about). Being caught up in the blood lust of the chase is not a good idea if the quarry leads into a deep quarry, for example. Yoda's remedy is again about attitude: consider the whole position and do things like making sure your thickness really is thick (there's an interesting new book on precisely this topic by O Rissei, incidentally).
More broadly Yoda advises us to '力をつける' - add 'power' to the position. But again this only really makes sense if you ignore the dictionaries. What he really means is '
latent power'. That is, things like adding a quiet honte. A passively submerged rock is probably much more dangerous to a boat than a rock of the same size aggressively lobbed at it from a catapult on shore - you can see it coming, can maybe dodge it, and it may only cause superficial damage if it hits. Or another way f looking at it: Highland charge attacks incur massive losses if they fail, and invite counter-attacks. Encircling attacks (the way of the surrounding game) frustrate the opponent as they give nothing away and leave few openings for counterattacks.
aggressive if it were wrong.