Man, the people defending this rune system make me simultaneously laugh and weep at the state of humanity.
News flash, that classic grind you guys adore so much is dead and gone, replaced by greed. Old RPG games used grinding to pad the gameplay so you didn't feel like you wasted a months worth of allowance to get that game, it was a more consumer focused thing. Nowadays you have the grind used to bilk people out of a lot more money than any video game should cost (remember that kid who spent thousands of dollars on some shit freemium game?). This grind is specifically calculated to browbeat weak minded fools into coughing up tons of money.
Oh sure, you can't buy runes with money, but guess what you can buy with money? Champions, which saves your IP for the hellaciously overpriced hexagons. IP boosts to double the speed at which you can get the shit. Rune pages which you need to put the things in. Riot claims this isn't pay to win, but that's a blatant lie. Until you've played about 5000 games or so and can get enough IP to get on the same level as people who bought the boosts, and the champs, allowing them more options to counter you before the match even starts, you're behind in many respects.
Why do you think they reworked the early runes but didn't touch the tier 3 ones? To give the impression that there's a fair currency system, look at all these shitty runes I can get from one match worth of IP! Then you get to tier 3 and oh shit I'll have to grind an entire month to get a decent page together, how competitive! Why do you think they removed the rune combiner? Now that tier one and two are dirt cheap, they'd lose their ass if they allowed people to combine those up to tier 3, and we can't have anything making the tedious rune grind easier, so that goes out with the trash.
The thing that should encourage continued play is having an actual decent game, a game where the players want to play by choice, and not a game that just hypnotizes its players with a shitty Skinner box model. Of course, riot can't actually do good balance because they have an unshakable iron man boner for Lee Sin and the rest of the big plays brigade, so of course they'll have to resort to smoke and mirrors to keep players interested.