I think it's a good idea.
First, SMD components may be cheaper, but placing and soldering them costs time and money. I doubt you could sell a fully assembled and tested product for less than a kit.
Second, through-hole soldering and SMD soldering are different skills, especially if you use some of the smaller packages like TSSOP or QFN. If 'can be assembled by the average mortal' is one of your design goals (and it's a darn good one), taking the difficult and high-chance-of-failure work off the customer's shoulders is a good thing.
If you get right down to it, that's the same reason we sell people a professionally-made PCB rather than expecting them to mask and etch one for themselves.
Producing a kit is a service. We do the time consuming and cheaper-in-volume stuff so our customers can do the fun and best-handled-individually stuff. If setting SMD components is a hassle your customers don't want to deal with, by all means do them the service of taking that unpleasant job off their hands.
vputz wrote:But then it's not a kit, and I like kits. Kits are cool.
is composed of pure awesome.
That's all the explanation you need. Anyone who doesn't say, "yeah!" to that won't buy a kit anyway.
When you void a product warrany, you give up your right to sue the manufacturer if something goes wrong and accept full responsibility for whatever happens next. And then you truly own the product.