I think it also has to do with what went into the regular version in the first place.

LC cheesecake and ice cream are basically low carb in the first place, so substituting splenda for sugar and upping the fat actually enhances what makes these things good.

Bread, though, is almost all carbs, so any substitutions they make are really crucial, and naturally some won't get it right.

And when in doubt, always remember Sturgeon's Law: 90% of everything is s**t.