I think you are underestimating the range of behaviours here, and its intent.
At micro stakes, players are often playing a number of different games trying to find the game where their edge puts them ahead. Lots of SpinNGo type games use the post-flop donk as a strategy.
In non-spins, donk bets are useful for pot control and putting uncertainty into the erstwhile aggressor. Over-pair, under-pair, flush and straight draws. Some bet, some call. But betting is a better option if you want to probe your opponent's post-flop strength.
I'll do this sometimes with a set. It is a happy medium for a slow play. It ensures chips go in the pot, especially in multi-way pots.
Donk bets are also often assumed to be noob bets, so it is a great read herring to do at a new table soon after sitting down.
But in the end, donks are useful for destabilising an aggressor. C-bets on their own don't tell us much. But post-donk behaviour in your aggressor can be quite telling.
I also like to donk when I've called a bet from the blinds and a low, board with obvious draws or having hit low to mid pairs. The one chip bet is gaining popularity. It also
tells the aggressors with AK, AQ, AJ that they must hit to get paid and that you're not going to let ace--high walk away.
Now, as the aggressor, you can decide to ignore it and proceed as if it was a check, but I think you'd be foolish to not at least consider the possible implications.
You can tell if the board has draws. So if you can avoid an ugly board, carry on betting. Make the donk uncomfortable. Afterall, your range will include AA, KK, QQ, JJ along with those swing-and-a-miss AK, AQ, AJ hands...so it can be quite dangerous for a donk to proceed against further strength.
A check turn and bet river if you hit (or want to represent having hit) will put your donk in a tough position if an over-card comes on the river after missing the turn.
At the end of the day, consider the weapons in your arsenal. Donk bets of pot size are great for
bluff-steal, especially from the blinds as your range can be quite wide.
Don't make the mistake of assuming its always a bluff, the equivalent of a check, or a noob. And don't rule out using it yourself...especially against Nits. You can take back 1/2 - 2/3rds of nits pots this way. If they don't have a made hand and don't hit on the flop, they'll fold to a pot size donk.
Towards the end of a tourney whoever gets the money in first seems to take the pot...so again, donks have their place.
TIME + PLACE = USEFUL
Cheers,
ObbleeXY