Suppose, you are using a solar charge controller. Out of curiosity, you unscrew the enclosure and find a whole Arduino UNO inside. Not an Atmega328P or any other IC. A circuit consisting of a whole Arduino UNO R3 connected to some components. Will you consider this design professional?
How are the components connected to the Uno ?
Other components are connected to a PCB. The UNO board is screwed with the PCB using hex spacers and wires are manually soldered connecting the UNO and the components. I came across such a strange product once in my life.
I would probably question why a smaller form factor board wasn't used.
It is definitely strange; not enough data to determine whether it is professional, and that depends on your definition of professional. Personally,y I would say N, O, since using the UN, O, the manufacturing cost is much higher than it needs to be.
BUT I have a bigger concern. Again, without more information, my gut tells me something is fishy here. If you really want an answer, you will need to show us the product, the purchase details and any documentation.
No, but was it sold as "professional" in the first place?
Or as open source development kit...
'A start up company' was selling that seriously!
Certainly a way to get a product to market quickly but probably not the best PR move.
Sounds like a "deliver fast, fail fast, learn fast start up".
Possibly they lacked funding to make it cheaper...
Or maybe it's some sort of scam.
This was what I believed.
Why can't a genuine or clone Arduino be a charge controller? I use Sunlite ("Shimano" clones) on my 1973 Raleigh and 1959 (oops - thank you Em) J.C. Higgins (Sears & Roebuck, 3sp Sturmy-Archer). If it fits, it ships. Heck, I shipped my pants!
J. C. Higgins
Spent many a moment thumbing through the Sears & Roebuck catalog next door to the Post Office.
If they guarantee that it will work within the given specifications, then who cares.
Sounds silly if arduino development wasn't the selling point. Is Uno genuine or clone?
Why does this matter?
Just for curiosity...
A genuine UNO buried inside some commercial product would be better than finding a clone.
Slightly, at least. 
a7
And how would you feel if you found not the UNO, but an area on a nice PCB that was exzctly the UNO: schematic, layout, components and all?
See post #14.
a7
Professional means you make money doing it. It doesn't always relate to quality. I'd say they could make more money and save space and weight by using less than a full Arduino.
You do realize that that the person who graduates last in their class in med school is also called Dr.