The argument: "Pro's made the switch so why can't you" doesnt really apply to the casual league of legends players. The professionals just pumped so much money into their accounts in order to level up fast, get quad IP boosts for their runes and they buy all the champions for RP, simply because it's an investement for their potential income (winning league tournaments). I simple cannot invest the amount of time and money into another account.
Mostly everyone who wants the transfer is in the same situation: We created a League of Legends account before there were decent EU servers, fell in love with the game and supported it by spending money even though the game is free to play. There is a substantial amount of income that these players generated for Riot. Now that we've all matured and are taking this game much more seriously after the ranked ladders and now ranked teams were introduced we want to experience the game to the fullest, without the extra ping that can impact our performance.
We would like our support for this game to be repaid by giving us the server we can enjoy this game on without having to sacrifice an absurd amount of time and money for content we already unlocked. Most of us will even pay Riot for this service (I know I would).
We know content is important. We know spending resources on this could not pay off in the long run but please Riot, consider the quality of life upgrade for so many players who have been with you from the start of this game.