No problem operating in/out of Finland, I think the problem comes to having staff (crew) based there where they may be subject to, or come under pressure to, be subject to Finland employment and/or union rules.
I agree with HW on this one. The cost of living in the Nordic countries is much higher than the vast majority of the other bases, so to pay the based crew there, they could probably afford double that in Eastern Europe.
It's worth also thinking that by the time you operate Finland - Mediterranean and back (as an example), you could have squeezed 3 or 4 shorter sectors in other areas of the network, giving more opportunity to flog those lovely ancillaries