In the absence of a firmly-defined “fundamental” equilibrium exchange rate, as the exchange rate fell, the market changed its view on what was the “correct” equilibrium rate. Even when most market participants agreed that exchange rates had gone too far, they recognised the possibility that they could go further still.
To stand against the run of the market in a contrarian position might be ultimately vindicated, but in the short run required a degree of courage and confidence that no fund manager (whose performance is evaluated more-or-less constantly) could afford to take. In short, there were no equilibrating flows to anchor the exchange rates. How should exchange rates behave?