The opposite of Lordship salvation is the "cheap grace" Bonhoeffer wrote about:
Cheap grace is the grace we bestow on ourselves. Cheap grace is the preaching of forgiveness without requiring repentance, baptism without church discipline, Communion without confession...Cheap grace is grace without discipleship, grace without the cross, grace without Jesus Christ, living and incarnate.
I can't help but wonder why cheap grace became so prevalent (and is still incredibly prevalent). Part of it has to do with the easiness of the approach, yes, where the will-to-easiness sculpted a theology that reflects this; part of it has to do with, perhaps, tribal theism, where our group is "in", and all we have to do is have the right culture (values and beliefs), and you're "out" because you don't.
But I think it goes deeper still. I see "cheap grace" as an inevitable consequence of salvation as a postmortem affair, "getting to heaven when we die." The reason is that because nobody really knows what it means to be saved and live a life in discipleship to Christ, salvation is pushed off to the unknown future world and all that's required is believing the right things, because what else is there for you to do when you have no idea what salvation entails?
If you understand salvation as what the term morphologically means, "wholeness" or "healing", which implies a present-centered state of transformation, also supported in scripture by Jesus referring to eternal life as
relating in a proper way to God (John 17:3),
and you know what's involved in
working out your salvation (Phil 2:12), then everything becomes incredibly relevant, and of course it makes sense to have Jesus as my lord,
because I actually know what it means to be saved under his lordship.