Is "Less than perfect" always used in a sarcastic and negative way?

Solution 1:

Seriously, although some have noted that less than perfect can be uttered sans sarcasm (depending on context), I hardly think it ever means a positive thing. Certainly it doesn't mean almost perfect.

Enjoy your day to its fullest. If anybody in the office makes your day less than perfect, go and talk to them.

Enjoy your day to its fullest. If anybody in the office makes your day almost perfect, go and talk to them.

Sentence 1 is saying someone marred the perfection of your day. Sentence 2 is saying someone helped make your day wonderful.

If you really want to use less than perfect to mean almost perfect you have to add a modifier of some kind to the phrase.

Her performance was only slightly less than perfect.

This means it was damn near perfect.

Her performance was less than perfect.

This means it wasn't very good, and the range of her failure is yet to be discussed.

Solution 2:

His vision was less than perfect, thus he didn't qualify to become a pilot.

I think there's no sarcasm in that sentence.

His love for her was less than perfect; he was always buying her gifts and flowers.

Solution 3:

It's not always sarcastic. It is always used in at least a moderately negative context.

The principle at work here is as follows: base probabilities are different than their negations. (It's been patented! In the medical sphere and related to probability, sure, but the same principles carry over.)

Without going into any of the (somewhat inscrutable) math in here, base probabilities (or goodness) and their negations aren't just p and 1 - p. If you look at Fig. 4, for example, 'always' has a probability of 99%, and 'not always' has a probability of 96%.

Now, comparing perfection to probability is a stretch, but I believe much the same principle applies - 'less than perfect', might very well be in the top 90% or even 95%, but it's not in the top 99%.