It is - Objects beyond 25lbs/~11kg may not be lifted via Alter Position collectively. That being said, incredibly particulate substances such as sand may not be lifted in large amounts more than a few grains. One may be able to cause rain around them to miraculously deflect off their attire, but throwing large globs of water is not a feasible task.
Look at the altered text, "Objects" (plural) beyond 25lbs/~11kg may not be lifted via Alter Position "collectively". Meaning that as a collective all the objects do not exceed above 25lbs/~11kg. Also literally seen in the example where it says you can move multiple particles of sand at once, or keep multiple raindrops from hitting you.