KISS - Keep it simple stupid. "All time high" is a perfectly descriptive phrase for what is going on, even if it is annoying and highly repetitive you'll never change what it is called. Trying to change behavior like this will never work because it is just such a common phrase. Even if you were to replace it with another phrase, I expect you would get bored of seeing that plastered all over after a while.
people are used to that phrase so really hard to change that. like teaching an old dog here. anyway, whatever you may want to call it, i guess, we all know what we are referring to here. thats the important part. the term may not be appropriate but people can recognise what it means.
maybe if you are writing a technical paper or something a professional document, you can use those appropriate phrases. but for just day to day conversation here, i guess we can stick to ATH as everyone understands what it means.