Sun UltraSPARC T1 had, if memory serves, 6 cores (with 4 logical cores each) all using one shared FPU. Nobody sued them and I don't remember anyone saying that it wasn't a 6-core CPU.
It's worth saying that Sun was fairly up-front about the limitations and I believe that official info said that performance suffered if the share of floating point instructions in the code exceeded something like 6%. In intended application scenarios - the so called enterprise loads that mostly just shuffle data around for a bunch of concurrent users, it ran circles around Xeon and Itanium competition with a comparable number of sockets, and that was good enough for people.
But it wasn't that different in AMD's case either. The Bulldozer (and Piledriver) CPUs performed very well under specific workloads and so and so in others and that too was well known, as a huge array of benchmarks and reviews was widely available.
It's also hard to claim having paid a premium for the chips when they were cheaper than Intel's mid range (i5), not to mention higher end (i7) CPUs. They were pretty much budget CPUs, some of them even had a launch price as low as $110.
The only possible exceptions are the 9000 series models, as those were expensive, but it's hard to claim that buyers didn't know what they were getting: they were merely factory overclocked models which launched almost 2 years after the first Bulldozers, end they were also reviewed fairly extensively on their own.
Additionally, FWIW, with AMD's share in pre-built system being what it is (and what it was at the time), the people who bought FX-8000 (and 9000) series CPUs were generally the people who build their own systems, not some uninformed poor souls who bought a box because AMD slapped it and said "This bad boy can fit so many threads!", so, IMO, this is either some buyer's remorse, or someone smelling free money.