Wonderbuck, you've clearly not mastered Ranger nor ever spoken to someone who has legitimately PvPed as one. The above statement is not only technically untrue, but anecdotally.
Technically: It takes ~1 second to fully draw an arrow on the string, during which the Ranger moves at something like 25% walking speed (much slower than Ice Arrow slow). As a result, if a Ranger misses a single arrow, the effect lapses and the quarry escapes as the draw time and resulting slow outpaces the slow effect of any single ice arrow that is landed.
Anecdotally: Arrows are incredibly difficult to land at all in PvP if the opponent simply uses the 'A' and 'D' keys due to lag and delay. Rubber banding is frustrating for you, but even worse for the Ranger you're fighting as it also makes landing an arrow nearly impossible. On top of that, the Ranger only has 13-15 ice arrows worth of mana, considering regeneration time. If the Ranger uses a barrage or any other skill during the fight, they will be running out of arrows long before your health runs out.
Long story short, please bring out a single mastered Ranger who will say the Ranger is able to effectively 1v1, or even find one that tells you that they dominate in evenly matched raids, then I'll consider this valid. Until then, realize that every character has at least 1 or 2 good abilities and that is why people choose them.