I totally agree. Using buttons with concise messages is best when they're used to access some functionality, but when submitting data the users have been clicking on submit buttons for more than a decade to do so. I'd even go on and say that in a lot of cases when you're submitting data, it's correct to use either simple actions as 'save', 'send', and 'submit' instead of 'Do the chicken dance when you click on this button'

Instead of worrying about submit buttons, which by the way generally exist a lone entities at the end of a form (which makes it's use even more obvious), worry about the actual usability of your forms and the logic behind the error handling.

tl;dr => In more cases than not it's more correct to use 'submit' as button copy than a more verbose counterpart when submitting forms.