Everyone tends to go to destinations “in season.” A lot of this is due to vacations (e.g. summer, holiday, etc.), while some of it is just responding to images you’ve seen (e.g. spring waterfalls in Yosemite, cherry blossoms in April in Washington DC or Japan, etc.).
Personally, I find lots of advantages to ignoring the tourist season and being in places “out of season.”
For example: Botswana’s typical tourist season is July and August, with maybe a couple of weeks into the adjacent months. That’s mostly Botswana’s “winter,” where leaves have fallen off the trees, everything is brown, plus the skies are clear and an ugly blowing sand color:
Meanwhile, April in Botswana is essentially their “spring" (end of rainy season), which means there is no “summer” per se. April also features fewer tourists—many times I was the only vehicle anywhere to be seen—and more color contrast allows for better imagery. The downside is that finding the animals in the thick foliage is more difficult, but when you do find them, you tend to get more memorable imagery:
There’s another reason to go somewhere out of season: it tends to be less expensive. At the Botswana lodges it can be as much as double the price “in season” as it is “out of season.” Considering that a good lodge tends to be a minimum of US$1000/day per person, double adds up very fast.
Bottom line: don’t follow the crowds. There’s more world out there than a couple of months when tourists visit.