Obviously I assume this is an American question as it says there is a 2-term limit in the US constitution.
True, if that's what the people want, why shouldn't they have it?
In countries with parliamentary systems, there is no limit. People vote and they get whoever the winning party chooses to be their leader. And if the leader is doing a good job, what's wrong with that? I'm British and it works for us in the UK. We tend to find, though, that it's a tough job and after about 10 years or so, the Prime Minister decides they've had enough and resigns. Tony Blair did that, and David Cameron said he would - though he ended up forced out earlier for other reasons. And if they don't get voted out first, that is. Or as in Margaret Thatcher's case, get forced out by her own party because she became too bossy and inflexible.
The US only has this rule because FDR got elected 4 times and people got to thinking it's too long. Then he died so it couldn't be any longer. But really, I'm totally with you. If you have a good leader and they're continuing to do a good job, why do they have to stop if they're willing to go on? What tends to happen in the UK is if one party is in power for too long, it looks like it's running out of ideas so we vote for the other one. But if it's still looking vigorous and full of ideas, why should we be forced to elect someone else?
People will say "it'll turn into a dictatorship" but why do they say that? With all the separation of powers the US has, how does that happen?