Doesn't seem that crazy to me. One site I looked at sells 300 capsules for $15 and the whole page is littered with clear warnings about overdose. The lethal dose of caffeine seems to be around 5 to 10 grams so you'd have to eat 25 200mg capsules in a short period to get into danger. That doesn't seem any more dangerous than something like tylenol which they do sell.
The danger is with powders, not pills. Dosing powders requires you have a scale that is more accurate than what most people have, and proper technique in weighing it. The best way for most people to get an accurate dosage is to compound the caffeine with some filler and weigh that (cut it, basically).
Honestly, the only reason you should be dealing with powders is if you're making your own 'stack' of nootropics.
I think the grandparents warning only applies to pure caffein powder. Essentially pills are (professionally) predosed to be safe, so it shouldn't be a problem.
