I don't think that "hints" themselves are the problem. The problem is laziness and accepting whatever you're given rather than actually considering it carefully - i.e. like the silliness of adding an English census return from 1871 to a person who emigrated in 1839. But that kind of attitude is encouraged by Ancestry as it sells it's ease of use and research as one of it's biggest draw cards.
But being a "young" researcher, who hasn't hasn't really been researching more than 5 years (and thus has never had to tramp down to the local parish registry office, which for me is on the other side of the world), the hints allow me to research quickly and easily and I wouldn't give them up. I can definitely give up looking at the hints from other people's trees, as they can be so inconsistent and inaccurate, but often I will look at those hints and in the end simply ignore them - usually after considering if they give me anything that might lead me to what I'm looking for. But then those are also the hints that you can simply switch off.
But I would not have been able to construct my tree, especially my maternal line, which is purely within the UK, without Ancestry (and to a certain extent, FindMyPast) and their hints. Especially since I work full time and most genealogical research places are only really available to me on my holidays. Hints make life easier and I have gotten better and better at assessing their accuracy as time goes on - and to be honest, Ancestry are pretty accurate when it comes to hints - usually you will get more accurate hints than inaccurate hints.
I have also been in contact with more cousins through Ancestry and AncestryDNA than I have through LostCousins. I have plenty of "contacts" through LostCousins, or exceedingly distant relatives who do not share any direct ancestors, but I have contacted 6-7 cousins through Ancestry and AncestryDNA - three to four of which I have been been exchanging information with and one whom I have now met. These cousins have gifted me with photos and information that I would never have had otherwise (for example, photos of the families of my great-great grandparents).
I do keep hoping that I will be able to get into contact with more cousins through LostCousins sometime soon!