As an interesting (perhaps?) side note, I tasted meat recently for the first time in 2+ years and it was really lame and underwhelming. :/
That statement is about as bizarre as "I tasted alcohol once, I don't understand what the big deal is".
My personal theory is that vegans put in way more effort to make their food taste good than non-vegans, and we eat an extremely wide variety of foods, so eating things like "steak" or "chicken" is generally a very boring flavor experience. I had a bite of "good steak" and thought...this is alright, but I could make better-tasting seitan!
That does not seem much better. You may as well say "I don't like alcohol, I tried 'good beer', wine, and liquor".
There are particular animals that I like or do not like (salmon for instance I have never been a fan of with any preparation I have tried) and various preparations/cuts that I do not like (lamb chops, most preparations of steak besides rare (preferably Pittsburgh rare, which is sadly difficult to find or prepare yourself at home) and most baked/broiled preparations of poultry). These classifications are again only scratching the surface of course, basically just breaking the question down to "ale or lager? white wine or red? Dark liquor, or clear?"
Regardless if it isn't your thing, then knock yourself out, but you should be sure that you don't fall into the trap of being confused why others don't share your personal preferences. (Or worse, trying to suggest that people who don't share your personal preferences are deluding themselves; lying to themselves about their own tastes.) I don't find myself annoyed by veganism/vegetariansim until I really get one of those vibes coming across.
Point being, meat is the most efficient way to get a lot of nutrients, and you can't declare that everyone can't eat it because you may someday discover that it's intelligent. The future is broad, we might find out that plants are actually the intelligent beings on this planet. Does that mean we should all starve ourselves now on the fear that that may happen in the future?
And effort, in my opinion, isn't enough to justify eating animals. Think about the specific efforts you go through to prepare raw chicken: you have to wash your hands in between handling it and your other foods so you don't risk contaminating them with salmonella. Way more effort than my dinner, where everything can safely touch!
Iron is more difficult in theory, but no other vegetarians I know have actually had a problem with it.
[1] http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2621.2002....
Additionally, the only vital nutrients in meat are b12 and iron, both of which are available elsewhere (lentils are great for iron & supplement is available for b12)
Apart from that, I would cede to your points about the b12 and iron, but if you want calories to sustain you, meat is definitively the most efficient way to go about it.
I make a vegan sandwich with 30g of protein and about 700 calories. Add a protein shake and a side of chickpeas and you're pushing 90g. It's shockingly easy (and healthy) to load up on vegan calories if that's your goal!
Because it tastes good. Just like every other type of food we eat that isn't a requirement for living healthily.