As has been pointed out up-thread (and is the reason why it remains in Dangerous Discussion rather than in PVP) the vast majority of times logging out using the menu timer occurs is just in the course of general play...NOT in a PvP situation...
That said, if you're so offended by the thought of someone you're in Combat with logging out midway through an encounter without any comms (because presumably you'd have to be a real d*ck to resent someone saying "GTG - RL -sorry!" part-way through an encounter) just play Elite with/against better people or at least initiate better encounters...
Your complaint seems to be I'm in an encounter with a random anonymous person on the internet and who I don't know/have anything in common with...I've initiated an encounter they DON'T welcome...and they've left without letting me have my fun..."
Firstly i dont buy it what so ever that the majority of players use of the 15 second timer is actual real life issues, not for a second. Also it isnt just PVP, its PVE when people openly logout if they are about to die.
Secondly; it may or may not be insinuated but i am not a ganker, i barely never PVP and the only times i have is when someone has pulled me out. I have been combat logged on when it has not gone their way. Getting pulled out in Open only happens to me if i screw up or let them, flying with awareness makes being ganked almost impossible.
I dont have a complaint, i just have an opinion as a minority in regards to this particular belief. I paid for the game so as unpopular as my opinion on this subject may be; i am entitled to express it.
This game, or at least the vocal majority on the forum indicates; is mainly played by people who do not like a challenge, and do not like a threat. A lot of people want to play this game to build up their own little empire and grind/collect stuff. You know what? That's fine! Under usual circumstances i would say "This isn't the game for me" and just play something else. The difference between us is i like a challenge, i want interdiction to be an "oh crap" moment not a "oh i best wiggle the stick a bit until he goes away" because lets be honest, who's losing interdiction's in PVE anymore?!? Anyone who is being honest will admit that their is no danger in the game unless you make it for yourself, travelling isn't dangerous and combat isn't hard to escape... There is also no loss, you lose something and a mild inconvenience pops up in the form of buy back. People don't like this, this is prevalent in the fact that the only 1 sense of loss this game has to offer (Crew) is whinged about insistently.
The thing that bothers me is that FD catered to this majority, with Solo and PVE mode (Private Groups). So why cant Open be dangerous? People know what they are getting into and choose that 1/3rd of the available modes, why should they have a "get out of any death" card? No one on the Eve-Online forum is whinging that when they log out prematurely or force close the game they are floating in space for 6 minutes, given how easy this game is why is it such an issue here? Well i know why i mentioned it above.
I like a challenge, i want a challenge and i know im not going to get a challenge but the money i spent on the game entitles me to put that preference forward, luckily the game has other saving graces that keeps me interested.
PVP in this game is a tacked on extra, its not PVP its a duelling mode, only consensual PVP works which removes the threat and the danger from the galaxy and that is just a fact; people just don't want to admit it so they hide the fact that its what they want behind thinly veiled excuses for features like "My pan is overflowing in the kitchen".
Im just going to leave the topic here, as like i said; i am in a minority in regards to thinking the ability to escape any consequence in a game that is already consequence free and easily avoidable is ridiculous.
Those are my reasons, take them or leave them

.