What? Long-Term Capital Management didn't use Black-Scholes. It hired Merton and Scholes, but used a completely different trading strategy.
They tried fixed income arbitrage with very high leverage. Black-Scholes ONLY applies to options.
The work that won the Nobel Prize had nothing to do with the downfall of Long Term Capital Management. Get your facts straight.
Variations of Black-Scholes are still used successfully in the trading world. The only difference is that no one thinks that returns follow a normal distribution anymore (but the Black-Scholes formula allows you to choose any probability distribution you want).