Well of course it's going to be an issue for players, everyone just wants to log in and play.
They are adding new servers, and upgrading the data centers for all regions just to support the current and expected demand, they weren't expecting this many people to want to play.
I mean you know I like you and I don't mean to be the *** here. But the "they weren't expecting this many people" is kinda ***. I am fairly sure that they are able to see the amount of game copy they sold.
All games get a peek of players at launch, which usually resolve itself a month ish later. No real game companies want to pay for huge server space. They know the amount of player will go lower and they pay for that average amount.
The annoying thing for ARR people right now is that SE does have the server space to handle most ppl (not everyone) but they made a login restriction of 10%, which leaves the other 90% frustrated. Doing something like this during a beta phase is totally acceptable, doing it during a launch isn't.
The main problem was ARR betas only lasting 1-2 days. Not all players were able to log on and truly test the servers. That and the fact there is no inactive kick out. There is no bazaar in this game, there is absolutely no need for anyone to stay online. But due to the recent attack of the "1017", I can't really blame them for doing so.
Not being able to play for 3 entire days because my time to play was always around 5 pm est, was quite frustrating.