He doesn't think it just because of that, this is just an example. That they had spread too thin with different products is a fact.
I got interested in them for mail, and I could undertand them having a few more things, but the constant expansion worries me too. Even worse if they amass a portfolio just to look nice to get sold and folded into some monstrocity like Google.
>They have a few core key products such as Mail, Calendar, Drive, VPN and Pass
Even those, do these sound as "few core key products"? Those are already a lot for a company like that (as you said, " they are a small team"). Especially when they keep adding other stuff too, like Notes now.