While I agree that these metrics can be subjective at times, I believe there are some fairly well-established features that dictate whether something is, objectively, a good product. In the case of a trackpad, gestures such as pinch to zoom are arguably an essential (for me at least), as well as stepless scrolling, configurable pointer acceleration configuration, and a reasonable size.

In the case of a keyboard, sure -- that's a whole other kettle of fish. I quite like the one on my Dell XPS, but I'm sure some others wouldn't.

However, I think you've downplayed how much a keyboard matters here: for me, it makes or breaks a laptop (or a USB keyboard, of course). When the laptop is on, I'm spending a good 70% of my time using the keyboard. Therefore, I would argue it is one of the most important things to get right.

I've come across good keyboards, bad ones, and ones that are just OK -- as an example, the more sponge-like ones on Logitech media keyboards do not make a good experience. In my experience, you have to try a keyboard to know whether you like it, but you can filter out plain terrible ones from other online reviewers' experiences.