Shuyin Kojima wrote:

I just can’t do evil. Like at all. I know it’s stupid but I feel guilty and wrong. I find I can’t escape my morals, even in games. Sure, every now and then I save the game and go to town on some faces, but I always load up my previous save.

Hey, everyone has fun their own way. I do find that having restraints now and then really enriches the experience. One time I really dedicated myself to being a bad guy, so I helped the hostile takeover of Goodsprings. I didn't feel good about it, and in the end I found it far more convenient to just leave the town alone, because as long as I didn't engage in combat with the Powdergangers I could still meet up with them at the Corrections Facility and have some interactions there, and another place to rest and restock.

I just wanna be nice to everyone and help with peoples problems

Evil and crime can tempt those who mean well in real life, when life is really hard. But in most games, you can end up fabulously wealth, powerful, and well-liked just by plowing forward and being the hero. Crime isn't necessary -- in fact it can make your life a lot harder in game.
A decent person might be tempted by a million dollars in real life, but in the game? Nah. In most games, I'm destined to get more money than I can spend, and become all powerful, by being completely and totally super-good hero-type.
All of my elder scrolls and fallout characters were like this. There simply wasn't any need to blow up megaton (along with all of its shops) for a measly pile of caps, unless you just want the world to burn and are playing as a psycho...which can be fun too, but it's not the temptation that I'm talking about. But if being a goody-goody character came at the price of being starving and broke, scraping for every last little bit of irradiated food, etc. then crime might be more tempting.

Mine's not really evil but more so only goes out of his or her way to help but only if they get payed handsomely. Pretty much that ol' merc lifestyle.

Nobody is "Evil". At least to themselves. I'm sure your perspective of evil and someone else's perspective are quite different, and the writing in New Vegas is done well enough to evoke questions of morality and how you rate morality against practicality and efficiency. Nobody goes evil just for the sake of being evil. They go "Evil" because the "Evil" side is where their priorities lie as a person, that's why FNV is written so well in my opinion.

Even though there's a lot of grey areas and so many people see themselves as good guys... good and evil absolutely exist in the fallout system (other than fallout 4) with an objective, mathematical meter. You could argue that this shouldn't be there, but it's there. That's what I was referring to... have I ever tried to play a high karma character and been tempted to the low karma path by some kind of irresistible offer? Not that I can think of.
You can literally potentially earn titles like "incarnate of evil." Usually it requires murdering masses of people just because they aren't murdered yet, but it's there.
But the original new vegas karma system was botched and not working well, so it could be why not many people play that way -- it's been ages since I played without karma-system mods, I sort of forgot how the vanilla karma system was. Probably a bad idea in that light to even ask this whole question. So many people have probably never even played with a fully working karma meter.

I prefer being in the grey area, going on a full good playthrough would be far too boring and a fully evil play through means missing out on some interactions.

I wouldn't say tempting, but when you've done almost essentially everything to do, what else is there left to do except population control lol

It's only tempting for me when there's loot involved. Other than that I actually find it quite difficult to be evil.

i can usually never play as an evil guy it just never feels right even if the rewards are greater. although the first time i ever played fallout i did kill everything i saw but i was young and didn't understand evil at that time