Suppressors are perfect for teaching new shooters, who otherwise might be put off or otherwise outright scared of firearms because of the loud booms.
Also, they're good for situations where you're able to shoot on your own land, but wish to remain courteous of your neighbors. Suppressors cut way down on that sort of noise, and instead of being the jerk next door who's always shooting his guns, you're the nice fella down the road who target shoots every so often but never bothers anyone with it.
Their legal status is that they are classified as NFA items, and as such must be transferred by a FFL with SOT status, and there is a $200 Federal tax in order to purchase/own them. That is a one-time tax.
And some people get offended when you call them silencers because some people are too uptight.
Although if I remember correctly, the very first ever suppressor was marketed as a silencer - but either is correct.
I think what gets the folks who will complain, is the fact that suppressors don't actually "silence" a firearm - they "suppress" the sound of the report. Therefore, the term "silencer" isn't technically correct.