You're basing your conclusion on how people use a traditional vaporizer. Yes this vaporizer looks suspiciously like a pen, but that's not where the stealth factor ends.
This vaporizer has a 5 second heatup time. Literally you can pull out of your pocket, click, wait 5 seconds, take a drag, click off, and put back in your pocket. Technically, you don't need to be "walking down the street sucking on a chunky pen".
There isn't any other herb vaporizer on the market nearly as stealthy as this vaporizer. Sure with concentrates there are a bunch of stealthy options, but dry herbs are harder to vaporize.
To me, the stealth factor is cool, but I'm personally excited about owning a small instant-access vaporizer allowing me to get a quick single puff before going about my business. All my other portable vaporizers require at least a 5-10 minute commitment