It is simple, everyone is free to make hundreds of accounts and to send Gifts to himself.you probably would not do it but many others will do it.Of course spending tokens for packs will decrease and perhaps disappear which Nordeus hardly want
For example if someone send to himself 100 green packs he can use them to train 1 player smt like 100 time,it follows that the teams will be full with 9 stars players,will be not interesting and will become pointless.