It's quite ironic that the ones complaining about a lack of open-world dungeons are the ones who actually asked for
instanced dungeons in the first place (i.e., the 1.0 players who SE polled back when Yoshi first took over as producer and director, and who asked players how they wanted ARR to be - I don't have a link but among other things I distinctly remember the poll in question asking players whether they wanted dungeons to be implemented as timed instances, or open-world, and it was rather overwhelmingly towards the former.).
Considering players also asked Yoshi back during the Beta if open-world dungeons were ever going to be added and he categorically said "no" (again, I do not have a source for this as it was on the now deleted Beta test forum), this is a case of,
gone horribly right I guess?
FFXIV may evolve and have things changed or tweaked as time goes by, but it's fundamental design will remain, which means, content such as dungeons and raids will continue to be implemented as instances and not just be made in FFXI-style as open public areas. That's just accepting facts.