I agree that there should be solution but friend invite as reward in guild feature is nonsense. I understand that many players can't invite because they putted themselves in such position but there are players that have less than 80 friends and this reward just doesn't make sense to them at all.
I do not need a motivation kit. Yes, it does happen, once for a while, that one of my buildings is not motivated. But I will no this not before it is ready to collect. So a motivation kit is of no use at all for me.
I do not use watchfires, but get them as rewards. From my laste era I have 25 production buildings I am not going to use.
There are already prizes that are of no value for some players. Why not a friend invite? Having many friends does look like a main goal of the play at the moment, with the friends tavern and all. So since it is a very important aspect of the game, the possibility to have more than 80 friends and nonetheless being able to invite a new friends just sometimes, in very special circumstances, is crucial. Much more important than to have a few more percentage of defence.