Originally Posted by
Rivin
Because if the line is going up linearly, each upgrade is less of an upgrade than the previous upgrade was. For example, if each upgrade gave you 10 strength (linear increase), you'd go from 10 to 20 (100% increase), 20 to 30 (50% increase), 30 to 40 (25% increase), and so on. So while, yes, they are technically upgrades, each upgrade is getting weaker and weaker so they will have less and less impact as you continue going up the line, and thus won't feel like upgrades eventually.