I understand that it seems redundant to go to HBL to load CFWloader to reload HBL again.
But the HBL installed as channel has more privileges, and some (future) homebrew might depend on that, so the normal HBL could be only used as "gateway" to the second HBL.
But, maybe we are seing this "issue" in reverse.
Don't see it like "you need to run CFW to run HBL", but instead see it as "once in a CFW, you can easily run HBL without the browser exploit, taking CFW advantage".
For example, if you load RedNAND, you get HBL installed in it ! it's more SysNAND -> redNAND -> you have HBL here. in that schema, you HAVE to run redNAND to see HBL. it's more like a bonus of redNAND (or a bonus of any CFW). what you see as an issue is because it's located on sysNAND (with and without sigpath). seing it on non sigpatched sysNAND might seems tempting to launch it from here, but you need a sigpatching step first.
Another solution if you want a shortcut for sysNAND is to install Haxchi on sysNAND.
now you have different solutions :
sysNAND -> browser -> HBL -> CFWBooter -> SysNAND or redNAND -> HBL channel
sysNAND -> haxchi -> sysNAND or redNAND -> HBL channel
sysNAND -> haxchi -> HBC Rpx (edit: but with the same privileges than the non-channel version)
in the 3rd case, you could edit the picture and logo of the haxchi game to be "homebrew launcher" (I saw some of these logo around the forum, users posted links to these files), making a "direct boot HBL channel from non sigpatched sysNAND" but like maschell said below, that method has the same privileges than the non-channel version.