No, that's not what I am saying. Whiteroom analysis does not appropriately value defensive options. I can also see where difficulties lie.
The problem put simply is that where decrementing life to zero equals victory, then on surface any amount of avoiding decrementing life cannot bring victory nearer. Designers have to think in terms of increased efficiency, losing the race less quickly, and creative use and utility. It is often difficult for players to calculate the true value of a defense at the table, so defenses you see most often used are those that fit well into the action-economy.
IMO. The problem is that in a team based game, high defense can be avoided by targeting lower defense allies. That is - defense only works as a tactic if the whole group matches (or nearly so, your investment). You need something that incentivizes enemies to attack your high defense character or the defense is basically worthless. For a caster that incentive might be casting a strong concentration spell. For a melee character it might be grappling the BBEG.
Because of the above the defensive traits that are highly valued are the ones that can prevent you from being disabled in combat (Resilient Wis for better wisdom saves) - which does tend to get recommended by whiteroomers.
Blur is an example of increased efficiency. I observe that it is hardly ever considered, yet casting it can save a great many more casts on healing spells. Counterspell is a great example of a defense that is widely used, because it readily fits into the action-economy.
Blur requires an action, only affects yourself, and enemies can choose to not target you after it's up (limited incentive to attack you vs someone else). Blur may end up preventing no damage (or more), does prevent you from concentrating on anything else, and requires a resource.
Contrast with Healing which leaves your concentration slot open, often just requires a bonus action, can target anyone in the party, and the slot isn't spent till it's actually needed (meaning it's never cast for no affect). *And that's before we get into whack-a-mole healing.
That's why Blur isn't valued highly.
Most valuations of defensive options are highly DM dependent and depend mostly on how the DM runs enemies in combat. Do they always target the turtle tank. Are they never willing to take OA's to engage another target. Etc. But if given a particular set of enemy tactical assumptions the right whiteroom handles defensive abilities just fine.
Another is the defense fighting style, which is often taken and certainly one of the top few fighting styles for value.
My takeaway from defensive style is different. Characters that go sword and shield tend to take duelist because it gives 'enough' damage and defensive style gives little defense. Characters that go Great Weapons tend to go defensive style because the damage from GWF style isn't deemed high enough compared to the +1 AC they can get. Maybe players should value the damage vs the defense differently but I happen to think they've already correctly figured it out.