When people in the industry talk about 'dumb money' they aren't talking about how informed or intelligent the order flow is. They are talking about how likely the order relates to market structure.
An individual investor who has looked at their portfolio and decided that the best move for their investment horizon is to move a big component out of equities and into bonds is still 'dumb money'. Even though that might be the most intelligent option.
A bot that has a terribly performing algorithm that takes market structure into account is not dumb money though.
What do you mean by "market structure?"
In reality for most trade-able instruments there are a variety of exchanges all operating at once. Further in each exchange there isn't a single price. There is a collection of buy and sell orders that combined together form the 'book'. For instance if you had 10 buy orders at $1 and 2000 sell orders at $1.10 what is the 'price' of that thing? The structure of the book and how all the exchanges relate (and Reg NMS in the US equities space) are all the 'market structure'.
HFT will take that bet on the other side of every retail investor they can get their hands on, including those with very sophisticated trading terminals. For that matter they will take the other side for very sophisticated non-retail investors so long as its non-directional flow.