Yellow (and other) rush decks are only easy to play, if their opponent doesn't know what to do. For learning what to do, I refer to my above linked guide.
In regards of combo decks being beaten by rush, I'm sorry, but that's just rush's job by nature, and a neccessity for the game's health on top of it:
A combo (otk = one turn kill) deck's strategy, by definition, is to draw for a big combo that wins you the game within one or two turns of actual play, without your opponent having any possible way to answer/prevent this (hence the tag "combo"). All they have to do is to enable their combo, which means drawing their combo pieces asap and storing up enough resources (faeria, colored lands) in order to play them all at once. In other words, they're like a timebomb - if you can't stop it soon, you probably can't stop it at all. The "deep strategy"-element is rather one-sided, because most of its strategy comes from deck building and the plan for the combo to become inevitable. When going "all in"-combo, you aim for setting up the combo as fast as possible, fortfeiting anything that doesn't serve this goal - for example competing for the board.
Due to that nature, the best general answer to these decks is to be faster. If you can neither interact with a combo deck's gameplay, nor defend vs. their combo in any way, being faster is very often the only possible way to beat them. And being fast is just the definition of rush decks. If a rush deck can't beat combo (because the combo being too fast and inevitable), usually no deck can. --> Necessary evil.
That said, I like playing vs both of them, but both have their own problems:
When facing combo, the first few times you'll be caught by surprise, which often leads to some exciting subsequent games of figuring out how to deal with them in a defensive manner. Because, it seems like there must be a way to stop the combo and there probably was some mistake, which I have to prevent next time, right?
However, if there actually isn't a defensive way (because combo being too efficient in terms of abusing even the smallest of openings), the excitement eventually turns into frustration due to actually being powerless (having no option to interact). It's like a really hard puzzle, which is exciting until you notice it's impossible to solve with the tools you have currently at hand.
When facing rush, it's basically the other way around. It's frustrating early on, because I know exactly what hit me (no surprise). It feels cheap, unstrategic (which it actually isn't) and quite often inevitable. It seems like you lost due to the opponent's deck being op and you having no tools to deal with it. However, more often than not, you actually have the tools to beat it, but don't know how to use them. Once you know how to do it, it's not that impossible to defend and eventually strike back. The previously pressured gameplay may then lead to exciting moments. Besides, unlike with combo, the board's strategic elements (faeria wells; importance of when and where to place which land) are actually used.
The biggest problem of rush decks is this burden of knowledge - you can't tell whether it's you or it's being op (most people often feel the latter, though it's not necessarily true!). Also, rush decks usually don't create a feeling of "wait, what was that? Show me again, let's see whether I can do anything about it". This is not a balancing issue, but a teaching/learning issue.