Seriously this thread is a bit mad - of course having 2 (or 3, or more) children is not its not "hellish" for most people - its just tiring and a bit stressful during some phases.
It depends hugely on the temperaments of both children and parents - sleep wise for example my 3rd was a non sleeper for so long that I was getting far more sleep when I had a 2 year old and a baby with DC1 & 2 together, than I would have been if I'd had 2 year old DC3 as an "only".
My DC1 needs constant social interaction, and can get that from her siblings - on the odd occasion we are 1:1 at home I don't get a second to myself, even though she's 8 now - when her little brothers are home I actually get more time to myself - not a lot of time, I'd count it in minutes :o but I can, for example, shower in peace as the 3 go down and get their own breakfast (DC1 & 2 help 3) and start before I get down - if its just DC1 she doesn't like to be alone so sits and talks to me while I shower - which is fine, its just that I prefer to shower without having to hold a conversation! Those are just examples, these situations are throughout the day obviously.
Of course during school time it would be "easier" just to have 1 school age child than 3 going down in age to a toddler - but not being the easiest option doesn't mean its bad 
or "hellish"
If somebody was thinking about going for a more challenging new job or going back to studying after a gap of decades, it would clearly be easier not to bother - but few people would try to dissuade them on that ground - they would look at whether it was worthwhile.
If you are very house proud or a perfectionist, more than 1 child is probably going to be stressful and maybe not for you - but if you can tolerate a bit of noise and have a DC1 who loves company, and is still quite young, it really isn't as bad as people are making out. I am finding this thread a bit over dramatic (my kids are 8, 6 and 2 - 2 kids was easy and for me easier than 1 as my first was so intention intensive before she had siblings old enough to play with and talk to, 3 is mostly fine and a lot of fun, but harder than 2) :o