I sort of agree that Eclipse started out that way (mostly paid for by IBM), but I am happy to report that the community has evolved a great deal since those days. If you take a look at the Platform UI project, for example, you will see a very diverse project, with a lot of unaffiliated committers.
https://projects.eclipse.org/projects/eclipse.platform.ui/wh...
The preferences window would be useless without its search box.
I found Perspectives odd at first, but I grew to like them. For the work I was doing, being able to set up a couple of modes, each with its own set of open and positioned windows was rather useful.
As to workspaces, I initially found it strange that I was expected to have like all of my projects in a given workspace, but Working Sets (or whatever the thing was called that opened certain sets of projects and closed all others) made that pretty reasonable. I did end up having separate workspaces for my C++ work and my Java work, though.
IMO Eclipse is a product of a particular type of engineering, one that is done on a 9-5 payroll, and never as a labour of love. I've always found it awkward to use and surprisingly difficult to configure - even simple things like syntax highlighting is spread over multiple locations in the byzantine preferences. The whole perspectives thing, and its obsession with you selecting a workspace, up front, which is distinct from the project you're working on - it forces the user to adopt its internal idioms and jargon, rather than the other way around.
Eclipse killed off JBuilder's original IDE back in the day, undercutting it. I far preferred JBuilder's UI.