Brazil failed in every event untill Loud. Riot didn't give our slots to EMEA or NA. They kept the slots as a investment in the region. The rest you already know. After two years BR made the most successful roster in this game.
Brazil and JP had very few wins in their first year at LANs. Then look what happened, Brazil won champions, and JP got 3rd at Reykjavik. It wasn't in an official league until this year, and they still managed to flawlessly win the East Asia LCQ. Give them time, and they'll grow as a region.