if you want to invite me to party, ASK ME first.

Most of the time, I will not ask. If you are in the same area I am outside of a safe hub, we're likely doing the same thing. It should be obvious what my intentions are. If you don't want to level faster and/or enjoy another persons company in the cutscenes, decline. I am not offended.

This is how I feel. However, if someone does invite me when I dont want an invite, I dont come to the forums and complain... I just decline it.

I recall, for example, a loading screen tip from WoW. It went something along the lines of: "It is considered polite to talk to someone before inviting them to a group or requesting a trade with them."
For what it's worth, that may be considered memo, sent by a longstanding, much-played MMO ; )

Back in the day this was an issue in the CoH/ CoX forums, too. Before they implemented the ability to block invites in that game blind invites were rampant. The problem was also that the invite window was large and when it popped up on the screen obscured your view.

Then people started sending tells first, but the tells were followed in 2 seconds by the invite. It was the jack*** way of saying "well, i did send a tell first!". I ended up always autodeclining invites because of it.

Anyone who declines an invite because I "have to ask first", gets instantly ignored. Your being a pompous **** and I dont have time to deal with uppity idiots in the little bit of time I actually get to play.

So you shove your money at the busdriver.
This clearly indicates your desire for him to take you somewhere, right?

Except .. he has no way of knowing where you wish to be taken to. It's not that he minds driving you there, it's that he doesn't know where you want to go.

Now imagine this:

To busdriver: "Hi, to *insert destination* please."
The busdriver accepts, or let's you know this bus isn't going in that direction.
You hand him your money in the first case, you leave the bus and wait for another in the latter.

Does that help illustrate the problem some people have with random invites? : )

On this topic,
If im doing my thing killing some dudes, and then i see onther person doing the same thing, sure i will invite them assuming they know im inviting them for the reason to just reach the goal faster. Now yes some of them decline and i just leave it as that. Im sure they are either almost done with the mission so they are on their way out, or they just dont like to group up with people. So be it.
Now i have been on the other end of the stick, recieving an invite from sombody that wants the credit for a mob kill. Again i have accepted and i have declined these invites depending on things. so in the end, just dont be a dick about it either way.

Some jackhole (not gonna name him) invited me 4 times while I was on the Imperial Fleet yesterday. I quietly declined each one and went back to my ship to run my space dailies. I kept getting invites even while on my ship. More than 15 total. I told him to stop but I never heard a word from him so I reported him. *shrugs*

For the most part, I agree with the OP. There has been the odd occasion, however, that I have ninja-invited someone nearby because they are obviously waiting to kill the bonus boss mob that I currently have at about 75% HP and I would feel silly finishing it off solo and forcing them to wait for respawn for no reason other than selfishness. I think I've done that all of 3-4 times and the individual has appreciatively accepted the ninja-invite each time and thanked me.

I do, however, typically decline random invites unless it's glaringly obvious as to why I'm being invited. Sometimes, I'm in my own little world and happy to be there. That said, I'm about as social as they come.

The invite popup in this game is tiny. There is nothing rude about just sending someone a join request. That IS asking.

Like anything else, it can be pushed to an extreme. But getting pissed by the very simple act of a join request because of this possibility is like being angry at telephones because sometimes a telemarketer uses it.