No. Just because it's there, doesn't mean you have to use it.
Personally I don't use iron sights that much because there's nothing they can do to help you play better than good old crosshairs can't do. All it really does is lower the sensetivity a bit to help weaker players and lower the spread a few percent, which may be useful in online shooters, but against regular Half-Life AI it wouldn't do much.
Personally I don't use iron sights that much because there's nothing they can do to help you play better than good old crosshairs can't do. All it really does is lower the sensetivity a bit to help weaker players and lower the spread a few percent, which may be useful in online shooters, but against regular Half-Life AI it wouldn't do much.