I certainly don't care for it much but I've been watching it. I'm not sure where you're at in the series but I would agree with you on everything from the point the Pegasus shows up untill episode 4 of season 3. The last couple episodes have somewhat returned to being at least entertaining. For whatever reason they derailed the entire momentum of the show for their little political side jaunt. Also it's as if they couldn't figure out what to do with the new ships and characters so eventually they killed off all the pegasus officers anyway and even Pegasus herself. It kind of seemed like the writers didn't like being out of their comfort zone with the extra characters and such and wanted their little 'family' all reunited on one ship. So with some notable exceptions its like they've returned the show back to where it was before the Pegasus ever showed up... (I can't entirely describe why this irks me so much). At least they're looking for earth again now.
The truth is actually very simple.
I have seen and several episodes of the original BSG (1978) - they are actually reusing the scripts from the original series - to some degree at leasts...
In the 1978 BSG, the Galactica meets the Pegasus several episodes in to the first season (IIRC, it's episode 12, but I'm not sure) it was captained by commander Cain, played by Lloyd Bridges, and disappeared (and assumed destroyed) in the next episode (or two). The 1978 commander Cain was not too mentally-stable as well (again, IIRC), but he kept commanding the Pegasus to it's end. He also appeared to out rank the 1978 Adama.
*****WARNING : SPOILER*****
Another example is the last episode (S03,EP10) in which the rag-tag fleet has to cross a star cluster with intense radiating cloud blinding eyes and instruments alike.
In the 1978 BSG Pilot episode, the fleet has to cross a very similar star cluster, only there the problem was the humans could not be exposed directly to the radiation (but only the Viper instruments were effected), and the cluster was mined by the Cylons.
There is actually a rather nice concept there, in which the Galactica launches 3 Vipers (Apollo, Starbuck and Boomer) in "blinded" Vipers (they coated the canopies against the radiation). The 3 Vipers clear a corrider for the fleet by receiving guidance and fire control data from the Galactica's bridge officers.
I guess there quite a few more examples, I just haven't checked
those two simple jump in front of my eyes