Sure a blender blends but it's not a one-trick pony. That's like saying a knife is a one-trick pony because all it does is "cut". As mentioned, your blender can chop, puree, crush, make vinaigrettes, etc. That stupid orange peeler thing that is supposed to make an orange easier to peel???? One trick pony and a gadget - useless!!! The blue egg separator - one trick pony and a gadget. It doesn't get the job done faster or easier...one trick pony and gadget. But that's just my take on it.
Gadget and tool...which is which. I don't know, really. I'm not going to look those definitions up anywhere either...I have to make up my own mind. While my lemon/lime reamer might be a gadget to some it is a tool to me...it gets the job done easier and essential (which means it helps make things easier and gets things done faster) to my cooking. My zester is a tool - gets the job done faster and more efficiently than a knife. Everything DQ listed I consider a tool...they are useful to me in my kitchen and make cooking easier. So...it's just a matter of perception on what those two words (gadget and tool) mean to you. A gadget is something that I have around and really wish I hadn't bought!
i.e., that silly orange peeler thing and the egg separator to name two.
Sure, your sandwich maker is a small appliance...as well as your blender. I think they are essential tools to have. A tool can be electrical or not. I consider my blender wand an essential tool...even though it is a small appliance. A tool is something that helps get the job done...electrical or not. A knife is an essential tool.
When it comes to a question like this remember...it's opinions you will get. My opinion is not wrong, DQ's opinion is not wrong, GB's opinion is not wrong...the world will not stop turning because one of us thinks a reamer is a gadget and the other thinks it is a tool...good food will still come out of our kitchens.