Carla G wrote:I remember when I was working for SYSCO Foods they had about a bazillion varieties of potato products to offer restaurants. One of them was a mashed potato with skins and lumps. It was a very good product. So, I never assume anything I eat in a restaurant is homemade anymore unless I ask and they say "yes" and swear to it!

I'd have to agree with Carla. There are many products out there that you would swear were homemade if you did a blind tasting. There has been marked improvement in the past five years or so in prepared side dishes.
Why would any one use them? While mashed potatoes are pretty easy to make in small batches at home, the amount that a busy operation goes through on a day to day basis can get pretty labor intensive.
They are hard to do in large quantities and keep consistent. I don't care how good you think your recipe is, they never, ever come out the same way twice.
Peeling potatoes is a chore no one really likes so can you imagine doing 2 or 3 cases every day? Also if your kitchen doesn't have a steamer, and most don't, then imagine wielding large, heavy, scalding hot stock pots full of taters from the stove to sink to drain the water off.
Don't even get me started on ricing them.
Then depending on the size of the mixer you have, if you have one; You may have to make several smaller batches quickly before the rest of the potatoes cool off and get really lumpy and starchy.
Yes, I have been known to "buy" mashed potatoes in a pinch. Sometimes you just gotta do what you gotta do to make things happen.