Why Can't People Just Say That You Have the Wrong Number?

It isn't a huge request.  It really isn't.

So today I sent a text to someone who I hadn't contacted in probably a year.  And I immediately get a response back saying "Hello!"  Then starts a very odd text conversation-

My response: Hi [name omitted]! I was hoping that this number was still a good one for you.
Their response: Wow.  What was the pic u sent?
My response: There was no picture, only text.
Their response: Ah...it said multimedia but i could not see ur first mssg.

So I reexplain my original message to them....

Their response: thank u so who is this?

So.....I reexplain who I am and why I was contacting them.

Their response: oh. i remember u. super cute.

Somewhere in the soundtrack playing in my life is the screech of a needle being dragged across a record.  This seems like an odd response from someone who I believed to be a woman in her 60s....but to each their own right? Maybe.

They asked: Debbie would u be interested in hooking up 4 some wild fun?
My response: No. I thought that this was someone else.  I'll remove this number from my contacts list.
Their response: Ok but i would love to lick ur pussy and fuck.

Uhhh..... who the hell responds this way to a complete stranger who has gotten the wrong number?  I mean really?
What. The. Hell. 
And on the other side of this....what if I was a total creeper and said "Sure, your use of "ur" instead of "your" really 'sends me baby'.  Name the place and I'll be there with no underwear on."
C'mon really?  What sort of effect does a statement like that ever really hope to have?
Couldn't it have just been easier to either not respond to the text or just write "I'm sorry, but I think that you have the wrong number"?