There are two situations, where a large open raise makes sense. The first is when opening from SB out of position against BB. To counter his positional advantage and the good pot
odds created by antes, it makes sense to use a pretty large size.
The other situation is, when you have a really good hand, and there are massive calling stations behind. If they are going to call 5BB just as much as 3BB, then why not make it 5BB and get more value. This is an exploitative strategy, which mainly works against bad players, so I would typically not recommend it in mid or high stake tournaments.
But if you are playing a 1$ tournament or a freeroll then why not? Maybe you can even open jam AA for an absurd amount of blinds and still get called, because someone think, you are a bully, and he wants to be the table sheriff.
Most of the time though a large open raise makes no sense in online tournaments, and people doing it are typically not the best players. Maybe they are used to playing low stakes live cash games in their local casino, and are new to
online poker. Maybe they just like to gamble and be the table captain.
Usually I will respect it quite a bit, the first time I see someone use a very large sizing, since it could be that exploitative strategy, where they raise big with their monsters. But if someone does it repeatedly, he will be well on his way to earn a “fish” tag, and I will pay close attention to try and get some reads on him.