Most contemporary hymnals (take the Trinity Hymnal (Revised) and the Trinity Psalter Hymnal as examples) have revived the lower settings of the hymns. The Trinity Hymnal (1960), for example, reflected the half-step higher setting to which organists in the late nineteenth typically modulated the last stanzas. The original keys have been restored in the more recent hymnals.
The highest note typically in either of these contemporary hymnals is Eb5 or, rarely, E5. This is the upper range, to be sure, of the amateur voice and not all can hit it, and many cannot without strain. However, it should not be a problem if such notes are relatively few and far between, and they tend to be in both of these hymnals, which have few hymns with a high tessitura (an abundance of high-ranged notes, especially close together).
The problem, Jack, with your well-meant counsel, and I really do take it to be that, is that songs are carefully crafted and the entire tone and affect will be impacted by lowering a whole step, certainly two.
First of all, it would punish any music readers seeking to sing parts (surely there are some present) by making them take their parts down accordingly, something some could not easily do and if they could it would land altos and basses unduly in the basement. Secondly, then, it would be letting musical illiteracy set the plate. Why should that be? Why should what's easiest for the least trained singer among us set the standard for how we sing?
And lastly, what is lost in bringing down the soprano and tenor is worse than what happens to the basses. When you lower songs that are already comparatively low, i.e., singable by untrained voices (and that is true of the hymnals described), they lose their brightness, which not only can render them dirge-like but which dulls praise, diminishes gloriousness of sound, etc.
I appreciate what you're saying here, Jack, but, as right as such lowering might feel, the better songbooks have done that appropriately and we really should not monkey with what good musicians have given us for beautiful melodies and harmonies.
Peace,
Alan