it's pretty tough to go wrong with A attributes.
That's true. Attributes is the easiest one to not screw up. It's still possibly, mind you, but that involves a rather high level of ignorance (willful or otherwise).
Sure, but as I've said before in the thread, "traps" frequently refer to pitfalls that ensnare new players who lack much system knowledge or experience as to what works better. Players can certainly build useful characters with Skills A. I would say the percentage of new players capable of doing so is much lower for any number of reasons discussed in this thread. I'd even say new players building characters with Skills A are more likely to build a worse characters than new players allocating Resources, Attributes, or Magic to A. It's simply a lot easier to screw up.
I think this might be selling new players short. Even if you're brand new to the system, it's not hard to go "I want to be an awesome gun fighter, so I'm going to max out pistols and, uh, automatics I guess. Longarms too because I want to use shotguns sometimes!". I know people on this thread have already pointed out that raising multiple weapon skills is "bad" because it's inefficient, but there are also definite perks to it outside of min/maxing. Granted I'm looking at this from a roleplay point of view (where you're trying to come up with a character to fit a story and not vice versa), so that may be skewing my perception on what the crux of this conversation is about.
I agree wholeheartedly that with our huge list of skills that it's easy to waste points on skills that'll never be used, to throw too few points to make the investment useless, or to throw too many points into a skill to thoroughly bury yourself in diminishing returns. But this just comes back to my original point: Every game of Shadowrun I've played has had new people in it who have built their own characters (both homebrew and Missions), and a number of them have had Skills A. None of them have been useless to the group, most were still very useful and some were way more useful than we imagined. This is why I have a hard time of saying "Skills A is a trap", because I have never actually seen it produce a useless character unless someone was purposefully making one to prove a point.
And again, I fully agree that Skills A is the least optimal of the A Priorities.