Taxi route

I seem to get a lot of taxi routes that seem illogical.  I tried to paste two P2ATC taxi maps from recent flights out of KSFO to illustrate the problem, but I could not paste into this message?  I'll try to describe the routes,  Taxiing to 01L, It went on A toward the departure end of 01L then across 01L and 01R then left on L to M then back across 01R to get to 01L.  In another one to 01L from a different gate, it went on A toward the departure end of 01L to G then across 01L and 01R then right on L to M then back across 01R to get to 01L. I t doesn't seem logical to loop around like this and cross multiple runways, when there is a simple direct route to the runway.  I just ignore the taxi path and in both of these cases taxi on A to M to the runway. However, I then run into a problem where I do not get instructions from ground to contact the tower for takeoff clearance.  If I try to contact the tower directly, it just sends me back to ground for taxi instructions.  I have found that if I just taxi onto the runway and then contact the tower, it will then give me takeoff clearance.  I'm not sure what the logic is here, but it seems strange.

Thanks,

Doug