Actually, there is no difference, because Nival/Ubi has acted as if H4 (and by extension the features in it) were bad, and thus act as if it has never been made, and thus could not possibly have had any benefical effect on the game WHATSOEVER.
Nival/Ubi appear to have engaged in a policy of outright deniability of any association with H4, having stepped back to H3 in it's virtual entireity. Instead of merging H3 and H4, using that as a base, and then evolving the game - they stepped completely back to H3 and evolved the system from there, in a different direction. Since none of the features in H4 that were in H3 have appeared in H5 (as far as I can tell), that pretty much means they are ignoring it as if it never existed/writing it off as a complete disaster/waste of space.
I like your definition of terms - H4 vs "classic". This is laden with symbolism of the main issues with H4 - it is not H3 or previous. They changed things. By not including H4 is part of "classic" HoMM, you force a person to take sides, so that naybody who likes H4 cannot possibly like HoMM, because H4 is not "classic" HoMM. Basically, the argument sounds like a bunch of crotchety old men complaind about change and preferring the gold old days. Except, things have changed, because with H5, the crotchety old men all appear to be H4 fans...
I understand diamtric opposition, but I reallt don't see how people can think that not flagging resource locations makes for a better game, especially given that they already flag mines. If they don't like flagging resource locations - then surely the shouldn't like flaggable mines either? Perhaps after playing a few maps where the heroes have to visit mines every day or every week for resources will show them the error of their ways. To say "we don't want flaggable resource locations, but we do want flaggable mines," is just hypocracy... but that's acceptable because that's "classic" HoMM...
There will always be for or against on certain issues, but if people really liked HoMM 3, they should play HoMM 3. If they liked HoMM 4, they should play HoMM 4. HoMM 5 should be its own game, a mixture of H3 and H4, which is the next step in the line - an improvement. It's an improvement over HoMM 3, but it's not neccessarily an improvement from HoMM 4, because there's hardly any similarities between the two - even the good elements from HoMM 4, were ignored in their entirety, including the ones that should have been no-brainers given the design brief for the game.
being a fan gives me the right to speak for what I want, and for what I believe other fans want, taken from these very boards. And what they want is a better, more complete game, and choice. Heck, I thought those wants would have been obvious even without reading these forums. And that's what the rant about skills is all about - a lack of choice. The choice for whether or not to go for the ultimate isn't enough - we chould have the choice of how we go for the ultimate, and when we go for the ultimate as well. The limit to abilities removes these choices, and shouldn't be there. There are better ways of handling this, as have been mentioned on this thread - if they were really worried about powerful abilities needing limitations, then they could have drawn on the hero development of H4, which more powerful skills needing earlier skills (so you couldn't always go straight from Basic to Grand Master in a skill in 5 levels). But they didn't...
Also, I don't suppose I need to point out the hypocracy of your speaking for "the fans" in stating the H4 was the black sheep of the family. In fact, I know at least one fan personally who doesn't think this - me. But then, it would be hypocritical of me to point this out to you, since I too speak for "the fans"...
However, if Nival did listen to the fans and decided the H4 was the black sheep of the family, then while you may have proved me wrong about Nival not listening to "the fans", you have also provided additional support for my argument that Nival acts as if H4 never existed. After all, that's what people do with their "black sheep"...
Of course, it's not proven that they listened to the community - there's been numerous incidents of when neither Nival or Ubi have listened to the community, and the only time they appear to have happened is when the community was preparing to boycott H5 for being incomplete. Not to mention that Nival has claimed to be fans of the HoMM series themselves, so probably already made their mind up over H3 and H4 without ever needing to consult the community.
Not to mention the all-to-common case of selective hearing common with design professionals all over the world (myself included, as it happens) where you are looking for specific type of feedback - such as variations or improvements of a specific feature, rather than comments about other things or arguments for removing the feature. For instance, comments on how to improve heroes off the battlefield, without putting them ON the battlefield.
(On a side note about hypocracy in "classic" HoMM - if you can attack war machines, why can't you attack heroes?)