I think "knowing if you would get on" first thing was a benefit when the park openings were at 7am or earlier -- if you struck out, you could go be first in line at another park's rope drop.
Now, it's not really a comfort. Disney has now allowed HS opening times to creep up to the point where if you show up at HS at rope drop for an 8am opening, and don't get into a BG, you no longer have sufficient time to park hop elsewhere and get in line well before that park's rope drop. So now if you lose the BG lottery, you've gambled away your rope drop advantage at every park (since there is no such thing as as rope drop advantage at HS anymore), and your whole morning is going to suck, no matter where you spend it. (Slight hyperbole there.) This may be no big deal for the casual visitor, but for the infrequent one who's dropped major money and planned for years for a few precious days at WDW, a ruined morning or two is a huge, hairy deal.
I agree with you that there's no better alternative to Boarding Groups at this point, but Disney sure as heck could do its guests a solid by opening HS early enough for the disappointed masses to be able to rope drop somewhere else if they can't get a decent boarding group at HS. Given that the lack of adequate capacity and reliability on RoTR is a mess entirely of Disney's making and they're still promoting it with ads on TV and online every 30 seconds in an effort to sell HS tickets, it's the least they can do.