Given up on the B string. . . . .
It seems to that there are a lot of players who like what they know and don't like having to think too hard about what they are doing. They've done the "heavy lifting", can play pretty well and feel comfortable in themselves.
Some of these players will look around, see 5 string basses and think, "I'll have a go at that." I reckon 99% of those guys will give up and the reason doesn't really matter.
You can discuss shortcomings in the instruments as much as you like but IMO most of them will give up because they didn't [i]need[/i] to play a 5 string bass in the first place. They fall at the first hurdle because they didn't buy into the requirements and changes they'd have to make in order for the transition to be successful. You can play anything on a 5 string bass, McCartney played Beatles songs on his Wal, but there are a lot of songs where you [i]have[/i] to play a 5. If you're not playing any of those songs or it doesn't matter to you if you are playing them an octave up then you didn't [i]need[/i] a 5 string bass in the first place.
If you [u]want[/u] to play a 5 string bass, don't bother. If you [u]need[/u] to play a 5 string bass then work it out. Work through the changes and difficulties and if the first instrument doesn't feel or sound good find one that does.