In your opinion, do switches sometimes need a restart?
I'm asking this because today our NAS stopped working properly, and was only fixed when we restarted the switch it was attached to.
Good ones - no.
Bad ones - sometimes, but that's only because they're badly engineered.
That's really all there is to it, really - if a switch requires regular rebooting then it's either faulty, or just a very poor switch. That said, as with all things with IT - sometimes things do go wrong. If it's the first time it's happened, keep an eye on it but don't worry too much.
I've seen it more often with consumer routers (Especially ones doing NAT) that are being used in the wrong environment. In those cases, it's more likely to be the NAT table filling up or perhaps a CPU related issues which are really down to just misusing the equipment.
It's plausible that you have a consumer switch which is just being pushed too hard.
Restarting will achieve a lot of things, most of which can be achieved without restarting. One of the things that restarting will often do is clear the logs in memory, so you won't know anything about the problem after you restarted.
So if you are seeing this behaviour frequently, rather than just blindly restarting, take a look at what is going on with the switch (assuming that is possible with the switch - it may not be if the switch is consumer grade, or the problem is really serious).
Knowing what the problem actually is will help you fix the problem, rather than just working around it.