You are merely very hung up on nomenclature. They had to choose a keyword, they chose const. It's very common: people have mental models and pre-conception about what word means. From that point, when in a specific context where their innate expectation are not met, they can have one of two reactions: adapt to the specific meaning in that specific context (mental flexibility) or reject and rant that things are wrong (mental rigidity).
Different people will have different breaking points about when things have been stretched too far, meaning they are not willing to compromise on. Working with people who have not the same level of flexibility or rigidity or differ in different contexts can be a day-to-day pain.
Nomenclature is certainly not great, but the trouble as so often goes deeper. Bjarne has these "constants" and so he can't see any reason he'd need actual constants which are, you know, constant. If he recognised that he's got immutable variables, and not constants, then the need for actual constants is a little more obvious.
But not runtime constants. I do agree with GP in that it would've been nice to have actual constant values, but it is what it is. The last thing C and C++ need is more features. C because we don't want to ruin it, and C++ because we want to slow the death.
Different people will have different breaking points about when things have been stretched too far, meaning they are not willing to compromise on. Working with people who have not the same level of flexibility or rigidity or differ in different contexts can be a day-to-day pain.