The way I look at it is that it comes down to intention.
When Hero markets their 616, is it really their intention to trick people into thinking that its a Parker 51? Absolutely not, or if it is they are doing an exceptionally poor job of it.
All patents have expired, so its free game. (I am speaking of the Hero Summer Colour/359) The patent system is designed specifically to eliminate monopolies and encourage innovation.
Nobody is being fooled by these pens. When I got my 616, I knew it wasn't a Parker. When I looked at it online and decided to buy it, I knew it wasn't a Parker. When I hold it in my hand and write with it, I know its not a Parker. In fact, I can't imagine anyone who has written with a Parker 51 mistaking a 616's (even mine which which is buttery smooth and wet) writing characteristics for a 51. So where is the poor ethics or unscrupulous behaviour?
Hero is not taking any money out of Parker's pockets by making these pens. Neither are they taking money from Lamy with the Summer Color. If someone wants to buy a Safari, then they go and buy a Safari. I can't imagine someone seeing the Summer Color - which is emblazoned with "Hero" all over the place - and thinking, "wow, that Safari is cheap! I should buy that German pen from this sketchy Chinese website/ebay auction." It just won't happen.
I think you should only condemn/boycott these manufacturers if you can prove and intention to deceive, which I don't think is possible.
That being said, my Hero 616 wrote awesome right out of the box, and continues to write awesome. About half a bottle of Noodler's Heart of Darkness has gone through that pen now and not a single hiccup or hard start. That's more than I can say about most of my "real" pens. I use my 616 WAY more than my 51. As a professional writer, I make my living from writing with these pens, and I would say at this point my $5 616 is far more valuable to me than my $150 Parker 51 or my $600 Mont Blanc 149. I understand of course that not everyone has had this experience with Chinese pens and so take that with a grain of salt.