Well, this gives the false impression that you have to pay to be competitive in LoL. Which is far from true. The only thing that can be bought only with money are: skins, name changes and transfers between regions. The things that make you actually stronger (runes, levels) can't be bought directly with money. You can spend money to accelerate your's account XP progression (by a factor of two). But that's irrelevant for first account, as it's not the account that is the limiting factor - I'm pretty sure any very good player can make a level 1 account and beat me hands down using it, as I can beat with a level 1 account a person who just got max level with XP boost.
After all, we talk about a game where you have over 100 champions with completely different skill sets, over 100 in-game items to buy, all creating a huge array of possible plays and counterplays... That at the same time requires split-second reflexes, maintaining map awareness and, the hardest part, good teamwork.
Nobody is saying you can spend a lot of money and suddenly be able to beat a "very good player." Instead, you can spend money and gain a competitive advantage.
Actually my main problem with LoL is that you have to spend money to access champions. In DotA I'm used to having access to a huge complement of heroes, and a common strategy is choosing heroes specifically because they are powerful against the enemy team (counter-picking). In LoL it's a lot harder since you only have like 20 (or fewer?) heroes available.
Paying for champions is paying for additional content -- content that's free in DotA 2.
That's true, but you also don't need (or usually want) to unlock every single champion. Most players have at most 20 champs they're really good with and will typically play. There's also the new mode they recently added, ARAM, that will randomly assign you a champion from the pool of all champions. Playing ARAM gives you the opportunity to try out other champions for free, and if you decide you like one of them you can spend your IP to unlock it.
The total cost of all champions available right now is 443100
and the average number of IP per game won is 110.5 and 72 for loss. This gives a total of 4855.9 games at 50% win rate. Sounds high, but you may still need triple of that to actually know how to play all those champions ;)
No, you don't have to pay to be competitive in LoL. But a lot of players don't want to be competitive, they just want to have all the options of the game available to them (which they never will unless they pay money).
After all, we talk about a game where you have over 100 champions with completely different skill sets, over 100 in-game items to buy, all creating a huge array of possible plays and counterplays... That at the same time requires split-second reflexes, maintaining map awareness and, the hardest part, good teamwork.