Actually you do collect AY points from leisure flights as well! And probably better earnings than buying a cheap W class ticket to a regular flight.
From
www.finnair.fi:
"You can earn points on your package holiday if the flights are operated by Finnair and the flight number is AY1001–2999. Your holiday may be organised by a third party, such as Suntours, with a charter flight from Finnair.
Other charter flights (e.g. AY7000-series special order flights) are not eligible for point accrual.
Please show your Finnair Plus card at check-in in Finland. A return leisure flight will accrue your tracking period flight total by one. Earned points are for both ways despite only one way being marked in the point information.
European and Mediterranean destinations: if your holiday takes place in Continental Europe or one of the Mediterranean destinations (such as Rhodes and Mallorca), you will earn 2,000 points for the return trip.
Canary Islands, North Africa and Middle East: if you're heading to the Canary Islands, North Africa or Middle East on your holiday, you will earn 3,000 points for the return trip.
North America, South America and the Far East:if your destination is in North America, South America or the Far East (e.g. Thailand), you will receive 4,000 points for the return trip."