Open floor plans came about originally to fit more people into a space, and to get more work out of them (which it fails at doing, but the idiot management theory is that if an employee is on edge, then they will always be alert and productive due to fear of being seen not doing anything). And beneath it all is the "breaking down of barriers" BS that permeates the business (sales in particular) world. BS that ends up being nothing more than a bunch of needy extroverted people setting things up such that they can constantly yap yap yap all day long to the point that all their needs are met (at the expense of everyone else).
People forget that this "keep it lively" (versus not negative, though they try to claim that's all it is), "smile and say hi when we cross paths," "approach me and kiss my ass to make me feel good," "always be open and approachable and available" (read: always be there when I need something, then when I ask do it blindly and with everything in you so I get what I want, then nod your head acceptingly when I make up some BS excuse when asked to do something as though it was ever about anything other than me ensuring I get everything I want while ensuring you get nothing), and anything else that will avoid insulting me or hurting my feelings nonsense is something out of a Dilbert cartoon and should've been ancient history by now, not promoted as some sort of superior/modern/good approach.
I hate open plan offices. The collaboration argument is BS, because I can collaborate just as well when sitting in a cubicle as I would when in an open plan environment. And, as a matter of fact, the cubicle (or some other) setup would probably be better because we could huddle around someone's desk as necessary to discuss anything that needs to be discussed, then go our separate ways to work on what needs to get done. All without the constant tension, anxiety, and noise of an open office environment that completely stalls out any ability to think clearly. The only things that really affect collaboration are proximity, and how well the group can collaborate (can they work well together, do they like each other, have they minimized the effect of any idiot managers and divisive employees, etc).
I hate cubicles as well, but I love silence, privacy, and the ability to uninterruptedly do my work. And the cubicle set up allows that more than open plan environments. Also, most open plan environments are setup such that everyone can see what you are doing (as in they can stand over your shoulder and blatantly watch for no reason, or can end up doing so unintentionally), and in a way that would leave everyone in a state of paranoia thinking you're watching them. Anytime I see something encouraged that heightens fear/anxiety levels like this I start to smell BS. I start thinking that maybe this is exactly what they are up to.
Open plan environments are good for those that like annoying or squeezing others, who constantly need attention, who like sitting close to others, and anyone else that needs to discuss every single thing with someone else before they do it (but it's really that they have an aversion to thinking, don't know what they are doing, and would rather get someone else to do the work (while BSing that they are just being more open and communicative) then take credit anyway). These environments are also great for management, an entity in most companies that's always looking for a way to underhandedly (something they can laugh about like they're so clever for doing it) squeeze more out of people while making it look like they are giving them what they want, and are so nice for doing it. That is, it amplifies so many negative aspects that any good that it brings is overshadowed, and it seems like nothing more than gimmicky, self-serving, overly hyped, faddish nonsense.