>>45604482>GeodudeThere's why, probably.
Whether Whitney was hard is going to be different from person to person, but she took a lot of people off guard because she was a pretty notable jump in difficulty compared to Falkner or Bugsy. Her Miltank is a Pokemon with pretty good stats, outputs good STAB damage, can self-heal, and has a move that almost literally can cause it to snowball out of control. If you fought smart or had a type advantage, you were probably fine, but it's perfectly reasonable that some people were surprised when she stomped them.