I don't know arachnologistTo who's research are you referring? There is a long-standing view that the inability to interbreed is indicative of separate species. But, interfertility is also possible among members of different species.
A little more context to your question would be helpful.
You expressed an opinion? I missed that. There is nothing inherently 'bad' about cross breeding - certainly not from any scientific perspective.I don't know arachnologist
just my opinion
yeah really some scientist do that and they know it's bad to crossbreed