Cleric Divine Weapon and sorcerer and wizard Bespell Weapon: No scaling?

[Colette Brunel]

The cleric's Divine Weapon at 6th and the sorcerer and wizard's Bespell Weapon at 4th might make for decent incentives to alternate between sword and spell at earlier levels, but how come these do not scale? Various other low-level feats scale their damage upwards, but these do not.

How well do these hold up at higher levels without scaling?

[Garretmander]

If I had to guess, they're both made to trigger weaknesses instead of add straight damage.

So, they're situational, and non-evocation wizards probably don't want it as much.