My googling told me that the "Motiv Rockpoint' is a big box store bike. This means it has a cheap frame, cheap components, and will mostly likely die on you sooner or later. If you're going to buy it, don't spend any more than 50 bucks.

Mountain bikes make great commuters. I'm using a singlespeed mtb right now as my commuter and its big tires can roll over anything on my route. I'm in a fairly comfortable body position and I can throw a rack on there and carry whatever I need with me.

I know you only have a mile to go, but I'm guessing you'll start doing that mile then want to do more and more riding. That's how the addiction begins. So I would recommend finding a better quality used mountain bike. Go onto Craigslist and look for '90s era Specialized Rockhoppers or Treks. Then go try em out until you find something that fits. A good '90s era mtb from Specialized or Trek will have better components than that Motiv and will last for a long time. And, if you want, you can even throw better stuff on there when you become an addict.

I bet in a year or so you'll be looking for the local singletrack and a ride of mile will seem like a stroll in the park.