I started publishing poetry about 10 years ago. It is easy to write poetry because there are absolutely no rules about what it should look like. There are rules which are designed to make a highly polished literary statement but it takes a lot of work. People who like the classical poetry, where it rhymes, has structured stanzas are split on how to accept the new wave of poetry. Some like it, some don't. Turns out not using the rules carries the infamous price tag of careful what you wish for. Everything's connected.
Wanted to write a story so checked out books on writing, but didn't get enough out of them. Went to reading the internet and found plenty of ideas of what makes a successful story. I interacted with several indie editors and soon discovered that their style of editing and advice was based on how they personally wrote. That's how the internet works. A lot of it is personal opinion, and some of that is based on what people found that worked for them. The internet allows everyone to promote their work in their own style. You used to need an audience to have a platform. No audience, no platform, no performance. The internet changed all that, now one can perform to an empty house every night, a ready built platform where there are very few rules, and they only pertain to technical issues, almost all of which are already in place before one starts to do anything. Without a lot of research it is hard to know what is personal and what is based on age old tradition, unless one has had a real education in whatever it is one is trying to learn.
I think the short story on head hopping is that if done well, it works like any other style. It takes effort to do properly. One needs to be a good writer right out of the box or has to has to get in a lot of practice. Another old adage, if one doesn't succeed at first, try, try again, So why does head hopping get so much attention. When it isn't done well, it is too hard to follow, translate that into unreadable. It ranges from unreadable to best seller. I have the feeling that no matter how good it is written, some people can't read it. Two very good reason why it is rejected as style. First, it doesn't rhyme, no strike that, that's another story. First, if someone doesn't like it, it's probably going to interfere with the entertainment value. A lot of reading is done for the entertainment it provides. Besides not liking head hopping, there is the problem of how it can filter out readers from reading it. There is a very simple rule for less well written head hopping, the less there is of it, the bigger the potential audience without anyone ever reading it first.
It's not the genre, it's the audience that sets the rules for what is allowable. The romance industry is big, powerful, well read, makes money, and entertains a lot of people. It stands on its own two legs, writes its own rules, and is very supportive of its writers. The romance industry needs new stories everyday and to get that it reaches out to romance authors, new, young, old, experienced, freely offering support. Being a near future science fiction writer offering no sense of escapism, publishing in an empty performance hall, I look like a beggar waiting for someone to drop a bag of gold coins in my cup, but that's okay, I like well written head hopping or whatever it's called.