The reputation point system is really designed to ease people into learning to use the site effectively and eventually metamoderation tasks. While it shouldn't be punitive in theory, sometimes it is - especially when something is clearly out of scope. On main sites, question downvotes often indicate a lack of research, information, or something that simply isn't within the scope of the site. We often edit questions for new users if the issues are minor, and comment on how to make things better. Sometimes something simply isn't in scope
Using the appropriate tags is important because it makes it easier to find specific sorts of questions. We clear out bad tags cause its noise. As a new user, if you really need a tag, and can make a case for it, it'll be added. However reputation point system is dumb stupid pointless ridiculous are textbook invalid tags - tags are like salt. A little goes a long way, too much causes high blood pressures. discussion will do nicely. This is PRECISELY why you need reputation to post tags.
The problem with your original question is really that its essentially a broad purchase recommendation. While there's workarounds, there's no real way to post a proper, universal answer to handle 'why is my computer slow'. we typically handle this on chat, but yes, it kind of sucks that you can't do that, but once again, that low barrier of entry keeps spammers and all but the most persistent trolls out.
Handling a high traffic site isn't easy. We have a fairly large team of moderators, we have community mods, and people still do things like use tags we've asked them not to use.
Getting rep isn't hard. As I pointed out, you need ONE quality answer, or a good question. I've always pointed folk at ESR's asking questions the smart way or you could do what I did and look around. (I've asked bad questions. It isn't the end of the world).
The reputation system lets us do a few things. Firstly, its our first line of defence against spammers. Secondly, it ensures quality to an extent. Finally, people love imaginary internet points.
I'd add, that the reputation point system is integral to how we do things here. Get used to it, work out how we do things, and you'll get a lot more out of the site.