Here's why:
* Т (T) is the closest equivalent to the English "T" sound.
* а (a) is the closest equivalent to the English "a" sound.
* й (y) is the closest equivalent to the English "y" sound.
* л (l) is the closest equivalent to the English "l" sound.
* е (e) is the closest equivalent to the English "e" sound, although it's a slightly different sound in Russian. It's used here because it's the most common way to transliterate the ending "-er" in English.
However, it's important to note that Russians might pronounce "Тайлер" with a slightly different emphasis than an English speaker would pronounce "Tyler."