you said "I don't see much in wing chun that is not about hitting. " - I was disagreeing and pointing out that there is a LOT more to WC then being being 'about hitting'! And, I was giving examples. Without WC bridging technology, how do you guarantee the 'hit' from a position of advantage? surely not just hoping you're faster/luckier than the next guy! But at least we agree now that it is surely about more than hitting if you agree with my reasoning
From what you wrote it is stll all about hitting. The end goal is hitting. Loi lau hoi sung: pressure centre, eat space, capitalise on errors. And the goal of loi lau hoi sung? Lat sau jik chung. This is why we loi lau hoi sung.
I left out a lot of things to keep the list short. no big deal.
But no, lat sau jik chun is not the most important part. It all goes hand-in-hand. You can't have yin without yang. And in this case, you can't focus on basting fwd and hitting without also knowing how to receive/escort incoming energies/obstacles. Without first being able to deal with our opponent's attack/bridge/energy, we can't reliably hit safely - all you have is cave man punching. This is simple wing chun fighting 101.
Loi lau hoi sung (pressure centre, capitalise on errors) so that you can lat sau jik chung (pull the trigger without hesitation when the situation arises due to pressure you are imposing). The first part is pointless without the second, while the second is much less likely to work without the first. They do work together but the end goal is to hit, not to impose pressure and control. You pressure and control in order to hit.
Like I already said some apply, some don't. You will surely pick 5 that don't, but I can also point to 5 that do. But it seems you are only interested in arguing the negative, so no point in going further.
The point I was trying to make is that wing chun doesn't traslate whole (principle wise) to the ground (never mind the lack of usable techniques there, and the non applicability of wing chun biomechanics in many positions). You need to alter wing chun principles to be groundfighting effectively, maybe allowing some while ruling others out. This is because it isn't a ground fighting art! If you end up there, and especially if you are on top, then sure you may be able to use some of what you know from wing chun to pressure and hurt your opponent. But you aren't going to win any grappling competitions with it, and frankly, in any but the most biased view, there are better options.