I'm serious. It's obvious you've never played diablo 2 or diablo 3, so I don't know why you're arguing. Go play one of them, come back and then apologize for being stupid.
Also, no matter how many abilities they had in Diablo 2 they still had the option to level up those skills, which you would know if you played Diablo 2.
Diablo 2 is one of the most successful PC games of all time. I have two copies I'm looking at right now. I really hope you weren't just relying on thinking I'd never played it.
But seriously? Your argument is terrible. It strongly suggests that what makes "real RPGs" for you is a lot of artificial choices that don't really make a huge difference on how things work. That in the long run, it's better to have a lot of superficial points to spend that alter coefficients alone than it is to have fewer choices that actually alter how your abilities work.
Let's compare two similar abilities that exist in both games:
Bash. In Diablo 2: Powerful Blow that increases the damage done to enemies and knocks them back. In terms of mechanical abilities the first point adds +1 damage, +50% damage modifier, and +20% attack rating. It costs 2 mana. The second point adds an additional base damage, another +5% damage modifier, another +5% attack rating, and still costs 2 mana. Every additional point adds the same as the second point.
In Diablo 3: Brutally Smash an enemy for 150% weapon damage with 20% chance to knockback. It also generates 6 Fury. There aren't any points, but five runes: one changes the knockback chance to a stun, two adds two weaker strikes to the effect while removing the knockback, three adds a stacking damage buff for 5 seconds, four doubles the fury generation, and six adds an aoe shockwave.
Honestly just adding generators and abilities that spend those points creates a deeper game. Using Bash in Diablo 2 is just an attack. Using it in three enables other abilities through fury generation.
In comparison Diablo 2 offers things like synergies. So I can invest points into abilities I might never use because they add passive scaling to abilities I do! Or not. Since they're entirely percentage modifiers it often comes down to pure math as to whether it's worth investing in a skill for any reason other than unlocking a succeeding skill, especially since many Diablo 2 abilities are basically replaced outright by later ones.
So rather than deciding on your abilities because you want to use them, many of your choices come down to "I'm putting points in X ability because it makes Y ability stronger, not that I'm ever going to use X ability again once I have Y."
Your real choices in Diablo 2 comes down to what abilities you pick. Every point you spend after that is a matter of making the abilities you picked hit harder. You're still going to use them in the exact same way.
If I pick an ability in Diablo 3 due to it's relation with another ability, it's because it works well with that ability, not because investing points in that ability was a requirement to unlock it or having 20 hard points in it adds 40% damage.
Percentages are arbitrary. Having more percentage modifiers doesn't constitute more choices; they all amount to modifying the same values. The game is going to assume it's possible to have those values, often balancing around the assumption I'm taking them. More points =/= more choices.