Here are some points:
- they are grown up people, with even more experience then you. If you are big enough to handle suicide, they are big enough to handle it also.
- they are at least to some degree part of the reasons. Even by giving you birth in the first place, but also providing you the starting conditions for your life. My situation was not that terrible, but not great either. Shitty country, poor family, single mom, bullied in school, lack of communication... It's really not that surprising it came to this...
- If you stay alive, what it is really the benefit for your parent(s)? I can't find a good woman, create a family, make my mom happy... I gave up also on the idea to make a lot of money, there is just so much corruption in this world... People are simple creatures, there is no topics left to really talk about. So I actually see it as a good thing, to leave for her what I've saved so far, so she can live the rest of her life without thinking for physical needs.
- Will your death really be such a drama? Considering my empty life, I don't think it provides any benefit to my parent(s). There will be initial shock, sure, but then, it may be more peaceful, since they don't need to think what I should do with my life any more... They can focus on themselves, and stop concerning with me. I think it's a sign of egocentrism to think everything spins around us, and our parents can't have a better life on their own...
So it really depends on how bad your situation is. If you have a semi-normal life, it's always tough to end it, and maybe you should really consider alternatives. But if there is truly no reason to continue, IMO parents are not a factor. You can't live for them, it should be the opposite, and if you can't live for yourself, make them proud, your existence as a vegetable doesn't help them in any way...