For one thing, imagine you did not get to watch the next episode right away. Imagine waiting 4 years to get all that stuff.
It's not even being able to watch the show on demand that makes the difference - it's watching it now, after the fact, compared to at the time.
When the series was being broadcast, the level of discussion and speculation it sparked was massive. I remember people at work who weren't even SF fans discussing the new episodes and their implications, and online it was simply massive. For anyone who engaged with that to any significant degree, the level of investment in the show and the unfolding plot was far higher than it could be for anyone watching it today and speculating on their own. The potential for disappointment was therefore similarly high.