I think they are pointing out that you sometimes can't even afford a temporary hold. Put it in for a couple of days, take it out immediately for bills.
Not being able to invest is a sucky situation to be in but it isn't a third world only situation. Not everyone in first-world countries has money to throw around. As soon as people do they should be looking at paying off bills and debt, getting a house, paying off that house and investing in various investments (that last two steps a lot of people don't do), but not everyone is at the point they have money to throw around at times it might be beneficial to have that cash unfortunately.
Opportunities like Steem shouldn't be limited by how much money you already have. The ability to invest is good and the people who have the money to invest have (most of the time) earned it so they deserve to have the choice to invest or not, but it is terrible if success on a platform RELIES on this investment, as it just takes away from opportunities from good artists / creators that aren't in the best place financially right now. And the ones who aren't in the best place financially are the ones who stand to benefit the most from platforms that provide income, like Steem.
I agree people should have the option to invest (like they do /can currently) but I also agree with steevc that Steem should be for all and therefore I feel like investment should play a role (otherwise why invest) but it shouldn't have so much influence to make it so that you will really struggle to succeed without investment.
The trick to making investment matter but not be the be all and end all of success on Steem, I'd say is more social than anything else. People should vote for content they like regardless of size, not just for the people that they see have a lot of steem power and this sort of thinking should be encouraged. This isn't a Steem only issue. There's people who judge YouTube channels by their sub count instead of their content too and it's just idiotic. We should be promoting the idea of upvoting content that you like, not upvoting what you think will give yourself the biggest curation reward, nor upvoting just because someone is big so you assume your content must be good because of that (and vice versa).
I really hope everyone that is saying investment is essential to success on Steem are wrong because that means the platform is shit, and I like to think that it isn't shit. I quite like Steem and while ofc it has pros and cons like all platforms, I like it and if investment is the key, I like it a little less because I don't agree with already having money being key to success on a platform.