It took a long time to accept relegation because before the pyramid in its current format was established, lowland league was a backwater with a couple of decent sides and the clubs relegated would face massive loss of revenue. League is stronger now and with more clubs that have a fanbase (bonnyrigg, kelty, bo'ness from below, shire and berwick from above).
I agree though, bottom team in league 2 should go down, no chance of a play-off. No disrespect to the bottom half of the lowland, but if they were eventually replaced with the top sides of the EOSFL and WOSFL relegation from league 2 wouldn't be seen as such a disaster. For those relegated to the highland league it might still be seen as a potential slide into oblivion but that's another matter.
The juniors were invited originally but from what I understand it was a slap dash, last minute attempt at getting them onboard. Don't see how that's relevant to the point that the lowland should have more relegation places though.