Well, the rules say to point buy your stats and then apply racial bonuses on top. You can certainly fix that in your game, but it isn't the rules. Every wizard I ever played with started with a 20 Int, since it makes nearly no sense not to.
It IS odd. The problem is that the CR and EL system breaks down the more enemies you use. For instance, if your party is level 12, then you want to throw an EL 15 encounter to challenge most parties. That means either 1 CR15 monster, 2 CR13 monsters, 4 CR11 monsters, or 8 CR9 monsters.
CR9 monsters generally have such low hitpoints, AC, saving throws and attack bonuses, that they can barely hit a proper level 12 party and die in 1 or two hits from parties of that level. So, if you follow the EL guidelines on how to make encounters, you are using extremely weak monsters if you use 8 of them in the same encounter. These are the encounters that is isn't worth wasting spells in.
They cost 36,000 gp. If your DM is following the wealth by level guidelines that means that a level 9 character can buy one with ALL of his/her gold. However, the requirements to craft one are to be level 8 and 18,000 gp. Which you should be able to have with money to spare once you are level 11+. +4 items should be able to be crafted without a problem at level 8.
I'm normally in agreement that DMs should follow the RAI whenever possible. However, I don't see anything that even points to this not being RAI. It's a magic item in the DMG. It explains how to craft them. It isn't some magical abuse of the rules. And it was perfectly allowed and done in Living Greyhawk, the official campaign of WOTC.
By the time level 18+ came along, our characters had upgraded to magic items that gave +6 to all stats.
So...if a DM follows the rules in the book, then there is an issue with the DM? The CR system is designed to be used with the rules in the book. That includes all the stat items when you can afford them.
It's that the system allows people to become unbalanced. Which is a problem. I think the real issue is that a DM needs to work AROUND the rules in order to fix the system.