Plastic is bad for compost because it throws the heat of in the pile and can cause a spot to spoil
Plastic is bad for compost because it will alter the temperature during the composting proses.
bacteria
If the owner is too busy or uninformed or if the community has regulations which do not accommodate composting then it would be bad to have a compost bin. For example, a compost bin ideally should be attractive, durable, and stationary (but mobile if need be) to not constitute an eyesore.
Yes, some microbes are bad
A compost pile is compost in a pile or heap. a compost pit is compost in a pit or hole in the ground.
composting organisms need heat and oxygen to break down the compost. If you don't turn the compost, anaerobic bacteria will take over and cause very bad smell.
Smells bad (Please refer to Question 'Why does compost stink?' to solve odor problems)
The heat stays mostly inside the compost, that's why it is important to turn the compost inside out regularly, so that every part of the compost gets sterilized from bad germs. In open air compost heaps, the heat will evaporate as vapor, especially visible in cold weather. That water loss needs to be compensated. There is probably not much residual heat at the surface of a compost bin. Heat usually goes up, but in that case, the heat is not in air or water, but in the mass of the compost itself, so it radiates in all directions. A small container such as a compost bin would see most of the heat exchanged from every side.
Compost.
Those white maggots are fly larva (fly babies) and they will turn into flies. Chances are, once they are grown, they will mate and die right there in the compost heap. And have more maggots. So if you like the idea of flies living in your garden, no it's not a bad thing. If not, well....
Cedar Grove offers several kinds of compost. They sell landscape mulch, organic compost, compost with manure and compost mixed with sand. One can order the compost online.
No word is exactly opposite of "compost". Most object nouns have no opposite except for the combination of "not + (that object)". Not compost is opposite of compost.