Cost, especially electricity.
Now I'm running at around a fifth of the draw of a 600w including ballast, give or take since the panel pulls 138w from the wall, on something that cost me under $50 in parts and when you ain't able to work then every watt counts, especially when thinking about what would be needed to keep the small 4' wide utility room I use at a reasonable temperature. In a rented apartment, can't duct out through walls, etc, so when you start adding up all these costs it would not be viable compared to getting an ounce delivered every now and then.
Do the same sort of bodged up panel using only the 5730 strip the parts stay around the same price, power draw will be closer to 200 watts but the light intensity will be a lot greater. And then the next serious plant will suffer LST, practice will be had in one of the solo cup fun and games, so next yield should be higher.
As said, I want one vaguely successful grow before complicating things, get the basics right move up a step on the grow ladder. Try too much too soon, fucking it all up is guaranteed