The other side of the slow rotation is that the 738 is prone to tailstrikes, and Ryanair hammer tailstrike awareness in cadets, leading some to err on the slow side of the recommended rotation rate.
I recall RYR training material emphasising 2°/sec where the FCTM states 2-3°/sec with rates slower in longer aircraft. If you are targeting 2°/sec and you undershoot it’s easy to eat a lot of runway. The NG rotation also tends to “stick” at 8-10°NU as the tail enters ground effect.