Well, it obviously depends upon what sort of game you want to play. Problem is, I think there's a large set of casual gamers who think they want "all the crazy", but when they face some insane combo, or just a whole bunch of scoring super-walkers backed up by some riptides, are not going to have a good time.
You do realize that 6 of knights is 2250pts and $840. For 2k and $500. I could bring an entire armored company of 10 multi melta toting vanquishers that would ruin those knights. The knights aren't that impressive for their points specially above 2k where most armies can bring all kinds of silly sh!t. If it were 6 real superheavies I could see your point.
Personally my biggest problem with them is their cost. 140 for a kit that only makes 2 variants. Wtf. A baneblade kit costs the same for a bigger, better kit that makes 8 different tanks is a much better deal.
Real super-heavies? They seem super heavy enough to me.
Anyway, it's not that there are no counters. You say you could take 10 vanquishers, is that a good army, otherwise? I suspect not, or someone would do it.
You can also take whole army of drop pods with melta guns, but most people don't want to.
You see, the real problem here is the death of the "all-comers" army. I mean this is already a problem, but it gets worse with each of these crazy releases. Because it's not like you need ONE drop pod full of meltas to deal with these super heavies. That would be annoying enough, but the truth is you need like 2 or 3, or whatever your equivalent is. SOme armies just don't have decent counters. ANd if you take that specialized heavy vehicle killing hardware, you're less able to deal with whatever else, like flyers.
So the whole thing becomes matchup dependent, not about how good player you are. WHich again, has always been a problem, but it just gets worse, and worse, and worse.
