The only issue is people complaining it interferes with their filters. Adjust your filter outlet.
Nah, that's not the only issue with it. I agree that it's not a horrible plant, that it's good for veggie eating fish etc, and I have no problem with it in a pond. But having had it in my aquariums, I'm a duckweed hater too. If someone likes it, no worries! But I'll never intentionally have it in any of my tanks again. I have some at the moment, that came with the psuedomugli and moss I was given, but I'm working to eradicate it again. Wish me luck!
My main issue with it is how hard it is to get rid of it, once you have it. It's earned the nickname of "the herpes of the hobby". I didn't have an issue with it clogging filters, but when doing a water change it feels horrible getting all over your arm, it gets blown down into the tank either by the filter or when adding fresh water, or when doing anything to the tank really. Then it clings to a sponge filter or to the other plants in a heavily planted tank like mine, and makes a mess. It gets all over your fish nets, syphons and buckets. It just gets everywhere.
I regretted adding it almost immediately, but it took a good eight months of constantly skimming it off the surface whenever I did tank maintenance, and it hid, since it had been blown everywhere and got on all my tank equipment. It would hide under and within the other, less annoying floating plants, under the lip of the tank trim, in the plants lower in the tank, and using a net or something even with the duckweed all dried out and dead looking, would bring it back. It seems to be able to come back with a vengeance even from a curled up, dehydrated and dead looking leaf. I was removing my amazon frogbit from the surface and rinsing it out in buckets of clean water, trying to remove every trace of duckweed. It's a pain in the butt!!
I even soaked some tank equipment in a bleach solution in a bucket outside once. Life distracted me and I ended up leaving the bucket there for a few days, and returned to find several bits of duckweed happily growing in the bleach water!! It's impossible to get rid of or kill.