There is nothing inherently wrong with kemonos or TDAs or Boothcats. The reason they were ever bad is because they got overused and people got tired of seeing the same shit over and over again, or done in bad taste (tattoos, terrible head swaps, etc). 
So really, it's not that we hated kemonos, or anything like that (well most of us), but that we hated the overuse of them.