No it isn't; you just apparently don't know what you're doing. You know what I take to fight TIE Defenders? A B-wing. Sure, it's slower and less maneuverable, but it's forward firepower will chew a Defender to shreds in the initial head-to-head, and the AI isn't smart enough to avoid charging straight down your guns no matter which one you use.
RP putting a smiley face after an insult still makes it an insult. And clearly you didn't read anything I said.
I said when flying an X-Wing. I wasn't asking for what ship could beat a Tie-D, I was mentioning how it destroyed X-Wings. And to respond to your tactics, the B-Wing might well be sound advice, I'll have to take your word for it as I've not flown them much. However, while I can see it making things easier in a head on run, the Defender, on paper, will still win. It's got quad laser and ion versus the b-wings triple laser/ion and it's got equal shields. It also has close to 1.5 times the B-Wing's speed and that plus its hugh manouverability advantage means it'll run rings around the B-wing.
I dunno what difficulty level you play on but it sounds like easy. Granted, the AI never fires at MAX range but it's got precision accuracy (the kind that makes you think you're being cheated) on hard so even if you survive the head on run against one you'll be damaged enough to have no chance against the other two.
But anyways
Yeah I'd always wanted a X-Wing MK2 to combat the defenders. X-wings with the power-plants, shield generators, ion cannons and larger engines, from decommisioned Y-Wings. But then as you say, defenders are extremely rare so it was too much of an issue.