Eh, everything he says is qualified and couched as his personal preference. He actually goes out of his way to do this more than he really needs to.
I know, but RE1 has great design through and through, even the things he describes as tedious (the limited inventory space, limited saves, item box juggling). It is just Dan's opinion so whatever, but I might as well outline why I think those design choices elevate the game as a classic.
The point of limited inventory slots is to deprive you of available resources, de-powering you which makes enemies more threatening. This already forces the player to make tough choices: They could carry a weapon + ammunition to deal with enemies in tight hallways that are difficult to run past, plus a lighter and kerosene to burn away bodies (this assumes Jill is being used, which also means she has 8 inventory slots). Jill is also carrying 1 key item to open a finish a puzzle and a key to gain access to new areas. Additionally since Jill has less health than Chris they could either risk dying by not carrying a healing item to save on space for items found during exploration, or carry one to inure themselves from death or unexpected damage. This leaves 1/2 item slots left for whatever Jill comes across, or risk carrying no additional ammo or even a gun to save on return trips to collect more resources.
If Jill runs up against something she can't get past because of low resources or her inventory is full, then she'll have to backtrack to an item box wasting precious time. Time is precious because the longer zombie corpses remain the higher chance they'll reraise as Crimson Heads, further putting the drain on Jill's resources and time to take care of them, or risk trying to get past without using ammo.
Crimson Heads are a game mechanic designed to punish backtracking and safe play. The more time you spend running to and fro trying to play it safe, the higher the chance of encountering a Crimson Head. This serves to enforce the importance of inventory management, taking what items you need, what items you might need and leaving a few slots open for gathering new items or to complete multiple puzzles at once. There's not enough kerosene to burn every body, unless you're a super cool guy and can burn multiple zombies at once.
The purpose of limited saves is to minimize the effectiveness of savescumming (as in to put a cost on the player retrying routes to achieve the best outcomes). It's doubly effective because running low on Ink Ribbons means the player has to play for longer sessions between saves, increasing the chance of sub-par route performance and chance of death, and infusing tension in the current run as their safety net is far away.
Carrying Ink Ribbons isn't really a problem (as ArjanN has said) because there's an item box next to most typewriters, but it's more important in Real Survivor mode where item boxes don't have linked inventories.
That's not even a majority of the design choices but I'll cut it to just that. Basically every action has a cost to the player, even time because Crimson Heads, actions you take now ripple out into the future to a meaningful degree because they are all intertwined. And all these outcomes are directly modified by player skill and knowledge (zombie strategies, route plotting. degree of item conservation, where to use Old Keys, what area to explore, puzzle solving ability)
