I can think of things that are far worst. I kind of look at it a different way. I look at using a ".com" next to your logo as just another way to promote your website. And I personally don't see any problem with that.
Sure you can Google that company's name, but... I don't see the addition of a ".com" or ".net" as just spelling out the address of that website, but to advertise that the company has a website at all. I don't think for most people it is assumed that every business has a website, especially small businesses. And if their website is an essential part of their business process, promoting it is essential.
We do a lot of vehicle advertising and the web address is becoming more and more of an essential item requested by clients. IF the web address matches the company's name, I suggests adding the ".com" on to the logo as a way to reduce the amount of content on that layout. As you all most likely know. people driving past things like
signs and vehicles don't have time to read a book, so those forms of advertisements must be short and sweet.
That's not to say adding a .com/.net/.whatever is right for every business or on all forms of advertisements but attaching a .com to a logo can be a way to kill two birds with one stone. And if it is done in a tactfully it won't harm the overall look, feel, or purpose of the logo.