Well, gore, the biological species concept (that species are groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups) was not formalized until 1942, by Ernst Mayr. Furthermore, Mayr's own historical survey (The Growth of Biological Thought, Harvard Univ Press, 1982, pgs 272-273) lists several "pioneers" who grasped the "essential points" of the biological species concept, but the earliest paper he can cite is from 1896.
Therefore, if we accept your pronouncemnt, gore, we have to assert that every scientist who dealt with the indentification of species prior to the late 19th Century (and certainly prior to Darwin) including the very father of the taxonomic sciences, Linnaeus, and all those other creationists, were not practicing science.
The biological species concept is non-subjective and is therefore valid.
How often do you think scientists actually do tests and observations to adequately confirm the biological species concept fully applies in a particular case? The answer is, almost never (at least in the sense of full confirmation). No species concept is perfect, gore. Again, this does not mean they are not coherent, or useful, or that species don't exist, or can't be imperfectly but usefully indentified.
It does not matter at all who or when the concept was first formulated. Although let's note that Mayr is an evolutionist. However, that he should claim this is ridiculous. Humans have known that species can only mate with their own kind for millenia.
How often do you think scientists actually do tests and observations to adequately confirm the biological species concept fully applies in a particular case?
It matters not one whit to me whether they do it all the time or not at all. Those who make the claim that two apparently closely related species are different species and do not verify it by experimentation are not scientists but charlatans. Science is hard work, something which evolutionists are totally unwilling to do.
For an example of the charlatanism of evolutionists lets remember the often cited example by an evolutionist on these threads of a 'ring species'. These folk spent YEARS followin a species throughout Europe and Asia and concluded that they had become different species because they had different songs. Now this is total charlatanism from evolutionists straining the limits of credulity to collect a paycheck. Of course these charlatans did not dare or bother to see if they could produce live young.
Another great example of the charlatanism of evolutionists in claiming that some different breeds are different species occurred with the famous "Darwin Finches'. For decades evolutionists claimed that these were different species. In the 1980's someone went to the Galapagos and bothered to observe the finches breed. Guess what, the different 'species' mated very well and the cross breeds were even more viable than the non-crossbred varieties.
So yes, given the charlatanism of evo 'scientists', we do indeed require verification by the only legitimate way to tell if organisms are of different species.