In modern parlance, saying something “sucks” means that it is bad or defective. For example, “That new song by so and so really sucks!”.

However, if you have a vacuum cleaner that is defective, what can you say? “This vacuum cleaner really sucks!” is not actually a bad thing. You want your vacuum cleaner to suck.

Sometimes, a word is not usable in every context.

I just had to get that off my chest. Does anyone else have these weird thoughts?