How else would they fund the "pay £1000 get £2000" in bitcoin capital? The price is micro managed by central actors.
The number of Startjoin accounts may well be growing but the number of active users is not. It's the same 30 people that are funding every project but only when they are being given more coins than they are donating.
Yes, the £1000 may be from the premine, but we don't know for sure. The premine (or 90% of it at least) is for developing the ecosystem and rewarding participation. That's what it's used for.
When it comes to the number of active users I think you are living in a different universe than me. I remember there going days between each message on startjoin last summer.