It's somewhat simplistic to approach this situation with "good actions should be praised" approach. It works with small children, who might lack long-term perspective, but governments are not children, they are an organisations made up (or at least are supposed to be made up) of responsible adults. Actions of adults are almost never reviewed in isolation - any action is viewed with prior course of actions figuring into its results. Thus, a single good act might become meaningless due to some prior events. Moreover, relationships between people lead to different evaluation of same events. "International community" is not a monolithic entity with singular opinion on every single matter, but a collection of interest groups with very varied opinions, which are then disseminated in various languages over multiple media. And all of these groups have their own agenda - and that agenda might mean that instead of looking for positives in an opponent's actions, the group will profit more by finding faults with these same deeds. What you are perceiving is not necessarily the objective truth, and quite possibly not even most popular opinion of the majority in "international community"; it's just the most vocal opinion in your media of choice.
Now, reviewing the linked video - USA is not criticised for doing a good thing, but for their approach to the situation in general. It can be argued that even considering the humanitarian aid delivered, net effect of USA involvement of the lives of Palestinians in Gaza Strip still works out to a negative value. And remember about differences in values: regardless if you personally think that's true or not, you can be sure that based on history of USA's continued support of Israel (and thus Israel's policy towards Palestinians), there will be people seeing any amount of aid as insufficient to change this math - whether because they truly think USA mismanaged the situation, or because they generally view USA as a malign entity.
P.S. Note that the population of Gaza Strip is estimated to be ~2 million people. The airdrop consisted of 38000 MREs - even assuming these drops will be made daily and the contents will be distributed properly (and not hoarded for scalping, as happened in other cases), this will not solve the food crisis on its own. Since the (current) conflict started, USA authorised ~$180 million of funding for aid; but the damage to civilian infrastructure in the Strip is, by some estimates, in billions already, and the ceasefire is still under discussion. In this context, the "too little too late" view on USA aid does make sense.