Seeing as the Ju88 carries more, flies faster, and climbs better, and is better armed to defend itself than the He-111, it is very much unrepresentative for early war scenarios. You may claim it's old and weak, sure, but you put it up against Spit Mk.I and Hurr Mk.I and it turns out to be too much for them to handle.
So, yes it is obsolete and "weak" -- but it is vitally needed, along with other early war planes. I'd love a G3M Nell and a Ki-21 Sally as well.