I don't consider 5'8 to be tall, it's more like taller side of average. But anyway, being tall is not intimidating, it's VERY attractive. This is not a politically correct thing to say and I'm gonna get downvotes from the insecure short girls, but as a very tall guy, I'd never date a short girl. You have to bend all the time, dancing is awkward, you can't even be on the same eye level during missionary which ruins the intimacy of the position etc etc.
Some shorter guys won't approach you because they know how picky girls are when it comes to height, but it's not that they don't find you attractive, it's that they think they don't stand a chance.
I'm either 5"7 or 5"8, I haven't measured in a while. Generally I find that most guys are actually still quite a bit taller than me. I don't think guys will be intimidated unless they are much shorter. I've been out with shorter guys, personally it is a turn off, they may feel the same about a girl taller than them. But if you do really like someone, and you think they're intimidated, you could always strike up the conversation and ask them if they want to hang out sometime. It doesn't need to be overly formal, just, "hey do you want to come for a coffee sometime?" obviously don't do this with someone you've never really spoken to because that's weird, someone you talk to and are interested in getting to know better. If they say no, that's fine, you don't need to dwell on it any further, if they say yes, great, get to know them a little better and see how things go.