You mean this

On the flipside, in ye olde days people did not take nerdy guys with glasses seriously until Bill Gates etc. made millions, and now the tech industry revolves around geeky people who do all kinds of immature stuff.
Maybe traditional investors are just... traditional, and perhaps the world is changing?

HODL may seem immature, but what it really represents is the attitude of 'Wanting crypto not dollars'. This is in essence what gives value to Bitcoin; the fact people want to hold it and not sell it. Because if the only point of crypto is to sell it for dollars it would quickly deflate. What then is the point of holding? Because you'll be able to do something (or more of something) in the future. What kind of things? Well, for starters, Bitcoin is what you want to hold so you can buy other crypto. What's that good for, you ask? Everything, I say. Webhosting, gaming, buying stuff, subscriptions, social media, etc. etc.
Those who HODL are in fact the ones trading in their fiat to their new currency of choice: internet money

In fact, an increasing number of people are not even HODLing long term to sell it anymore. With payment solutions like TenX coming out there will be no point in selling your crypto ever, especially not when it keeps earning dividends or rising in price whereas normal FIAT money is subject to yearly inflation. I know I put fiat in, and to be honest, I am not trading it back into fiat for the next 2 years at the very least and if things keep going well I may not ever. I'll just earn more digital assets, instead. So yes, I do HODL in projects that I believe have significantly more value in the future. It's pointless to sell for 5% gain when there's so much risk of losing out, and you're almost always better off just sticking to the long term plan.