Adam,
So to paraphrase, you're saying that while a badly designed course can be possibly be "too firm" a well designed course can never be "too firm". Which would imply that one criterion for a "well designed course" is the ability to be played under arbitrarily firm conditions, no?'
I'll offer a contra-argument. In an area where the type of soil, type of grass, climate and maintenance budget make very firm conditions generally impractical would it not be desirable to optimize the design of the course to reflect those realities?
Why would someone want to build and maintain a course exactly like The Old Course in every design detail in a location where it will be playing too soft and wet to allow any meaningful ground game on, let's say, 300+ days a year? If firm, dry turf and running, bouncing shots are seldom going to be possible (and let's throw in the likelihood that the wind will seldom exceed 10-15mph) surely there are better ways to design a course than making a links course lookalike.
I'm not sure which I find more frustrating...
1) Playing a course that is soft and damp which requires elevating the ball and stopping it at the whole because of fronting and crossing hazards
2) Playing a course that looks like it would offer all kinds of ground-game options when in fact it is so soft and damp that 90% of those options are nonexistent.