Why do people say "like" instead of "love"?

Because both words can be defined differently between people. For example, if someone shows affection to someone, but not on the level they think is love, they'll moreover say that they like that person.
It depends on how the individual defines these words.

cause amor is a strong word

It doesn't mean the same. amor is harder to get. Like is más like "appreciate". amor is something much stronger.

amor and like are different things. Just because tu like someone does not mean tu have strong feelings for them.

Read the other respuestas ._.


But, like isn't as strong as love....

They don't.

When they mean love, that's what they say.