The logo cost certainly something extra, but (what a surprise with Canon!) To the fun not to indulge too much to. One might complain that it eg Tamron nevertheless manages to affix labels on the direction in which you can open the Deckelchen and close, but that makes you anyway so instinctively that it likely would be a joke, to skip over it and then there is just big Tamron and rather small for Canon plan.
Anyway - I have to sacrifice adapter for connecting lenses with M42 and Praktica Bayonet connection to my Canon EF camera and little desire, the good old glass of the dust, or worse, or then every time only remove the adapter, so had matching Deckelchen forth and do now work as expected, what they should.