This is a bad thing. I think after each season teams who do not have any activity during that season (no login in 28 days) should be deleted. Maybe they should be notified one week before the end of the season that they will be removed if they don't do anything.
Also it should be possible to stop after each season. 70 days is too long, in every competition (at the lower levels) there are at least 4 inactive teams.