Yes, although the chances are very small, it is much better to have just one ticket than none. If I had had zero tickets for a lottery round, I'd buy one, but normally I have hundreds of them from my WoF spins.
I do not see any bigger logic in that - except the fact that because of rules, each newly generated/bought ticket lowers others' chances. I just do not see point in doing something you are not fully engaged in. It is just spending money without any sense (for me), as real chances are so low that is it is really difficult to have any hope. I would love to disable lottery tickets completely, but unfortunately it is not possible and I still receive them from WOFs.
No logic in buying a ticket for just 1 satoshi? I don't see much of logic in keeping 1 satoshi either.

It won't be a lot of money even if BTC hits $1 million, right? So, I wouldn't call it "spending money", if you ask me. It's spending 1 satoshi and making your life a little bit more entertaining with that.

I agree if we are talking about simply just 1 satoshi. If you are left with an option of having 1 satoshi or having 1 ticket then I would say 1 ticket is much better option of the two, sure that ticket would probably not win you anything at all as well, but 1 satoshi was for nothing neither, you can't do anything with it.
But, if we are talking about the rate, you can gamble and earn so much tickets anyway, so why spend hundreds or thousands or even tens of thousands of satoshis to get the equal number of tickets, that's the deal. If we talk about let's say 100k satoshi or 100k lottery tickets, in that situation I would go with satoshi instead because you can do something with it.