How important is the Sharpe ratio for intraday strategies? Does anyone use it for the evaluation of the strategy? Thank you.

As with all things. It depends on your system. Personally, I am working on automated scalping strategies (typically only holding 1-2 bars on any timeframe I'm trading). I do pay attention to it and target a 1 in backtesting but I value my profit factor much more, I've found I can be under a 1 on Sharpe and very profitable still day trading but the higher the Sharpe ratio in my backtests the less painful the drawdowns are in real time typically (for me).