I would not say that items take more skill to use, but they do to use correctly. True, there is a random factor when it comes to items, which may level the playing field to an extent, but that does not mean items are all luck (and I knowyou are not saying that). I don't like putting items like bob-ombs and golden hammers on, since almost no strategy can be but into them. That's why we have a wonderful thing called the item switch. You can turn off the cheap items that have no down side to them and leave the ones that can be strategically used on. You can plant as many motion-sensor bombs as you'd like, but you'll be the one paying for it if you plant them in the wrong spot. Putting pitfalls on go-through platforms that are just above a hazard is a bit more difficult to do that chucking it at an opponent, but much more rewarding. Heck, even most power-ups can be used against someone (metal + meteor smash or footstool jump not over ground = guaranteed KO)! Also, remember that most items outside of battering and power-up items leave the user wide open to attack after use, presenting a golden opportunity to a seasoned smasher.
In my opinion, smash is (sort of) like a speedy game of wits. You need to anticipate your opponents moves, excute your own moves, be aware of your surroundings, and plan your own strategy. If you were able to predict what would happen all the time, the game would be boring and nothing would change. We'd be playing the same thing over and over and eventually just quit playing. Though I detest the use of cheap items in serious matches, maybe a homerun bat to the face is the wake-up call some people need to see that item use is not entirely skill-based or luck-based. Competition's all about proving superiority, and if you let a n00b own you with a dragoon when you could of held at least one of the pieces for yourself, preventing them from getting it, you aren't really don't that. On the flipside, I do agree with you that nothing sucks more than to do amazing in a match, only to be blasted by a blast box that just appeared in front of you. But not all items are cheap.
Anyway, I'd tell your friend about how Sakurai promotes an "everybody wins" philsophy over a "winner-loser" one. Just remember, you can turn off the bombs and keep the food.