Turn timers in turn-based strategy games are actually important for a reason other than preventing abuse. They're an essential part of the enjoyment. If you think you're a counterexample, please let me explain before you close out.
The fun of turn-based strategy games comes from thinking about what move to make. But the enjoyability of doing this gradually drops off as your thinking gets less productive - which it inevitably does the more time you spend. That's why people still pass the turn eventually if there's no timer: you reach a point where it becomes so boring to continue that you end it yourself even though this is against your interests of winning (since it's almost never completely useless to keep thinking). So the game is forking your interests. No matter how contemplative of a player you are, if there's no timer, you'll eventually have to choose between playing at the pace you enjoy or playing at your best. You can't do both.
The reason some people prefer such long time controls is not that they aren't subject to this, but that they consider it a lesser evil than feeling like the timer is preventing them from playing at their best. To them, having a tight timer contradicts the point of a strategy game, where it's only your intellect that matters. But it's possible to have a timer that allows you to feel like you're playing at your best, or close enough to be satisfied, without getting to the point where you end it yourself because it's no longer fun. That's the ideal timer that makes everyone happy. (Of course, the ideal timer length won't be the same for everyone, which is why it's important to have options for this; I'm just making the point that there is such a length for everyone.)
Obviously, due to the variance in how long a player wants to think there's no way to guarantee that they'll never be pressured on a move more than they want to. But a good timer system can come damn close. Prismata does it right: you get X seconds per turn, but if you finish your turn early you store a portion of that time into a bank that you can draw from later. This allows you to take extra long on a turn if you need, and also to be rewarded for playing extra fast. (And the reason it only stores part is to incentivize you to think on the spot instead of trying to read into the future.) Everyone is happy.
The real difference between "turn-based" and "realtime" games is that in turn-based games the timer is only a threat that's not normally executed. The timer tells you you'll be penalized if you take too long, but turn-based games make it a binary whether you "took too long" and make it not matter how close you were as long as you didn't (except that you'll have less time on future turns). The timer fulfills the purpose of limiting your thinking time to an enjoyable amount (so that there's no conflict of interest) without actually executing the threat in most cases. In realtime games being penalized for not acting quickly enough is ubiquitous; it's about how much you get penalized (in a real-time strategy game) or how often (in a fighting game).