That's their opinion.
Once upon a time, Justine Henin had weaker shots... and won with her speed mostly. Justine improved on that. However, Justine had naturally very fine strokes. I don't think Bepa really lacks power... so, it won't be that easy.
ys has said that Bepa's main problem is mental. Yes, it has cost her matches this year... but I think she needs more than that. Everyone is entitled to their opinion, however.